501b721387
-----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEZH8oZUiU471FcZm+ONu9yGCSaT4FAmUOpmEACgkQONu9yGCS aT6vSQ/8D3yjJUYiUnHkiSzTMZHAtwR5qk0jCsqw1Xlr+XVouGCG/wpk8z7ckT6W 4gsG5+QvuB4SfWXmbIn/rPApqQdQSiTicOfHrev705v0U+ib+kw1vgBKv38qkOlI EZKuo7Ir1vZUnqghw9uIGperU3kEAt2EvWK37EBryukDoxbzDGIctOvAN7KMMbAJ jPQciVOOAJrNNdgPOSrxs1OCdAkEYlDaNuBZ+9j/HjNQLB9KtdtsJ50gerCPA4rS oKpZhnx9VJYXI9szor3T7q71iNfpJeL+mOrnpCSFVAFCPkesXQ+MG/GdgJJQDCMJ 9VF12W6rpqVcKfYFdPX9WevkqMfHRpE4brotDQx36rpUwVFcP7HClJ2zE3p36QWV Mfu4O31ZNkLUF8SmFXc3JXVyrwe/ARiha9nLH9VKZ7cSHoYUKlO4NeSGyHjz5J99 RErBGpea7SgHTSLk30+sHaB3zhdUZyv8ej++zjTG9QA8bRbMp97I9psQ7FWhWDng l6f87mdta1X76OJJPkL3yZfbiB/M58e514ptbDNhu4cnH/S6aB6I3K5IYVtfZI/9 zESuavKEUks+Ng1vBUGsPGN/eHDaPWUkl7HewP7WXRDOQUjaIX/0saeaSiUFYNI7 UYa72hD9fKMblkwxIl75ybI/WZRgw9fyrQeGG0DfX3t6kt6BhHM= =bQT4 -----END PGP SIGNATURE----- Merge 4.19.295 into android-4.19-stable Changes in 4.19.295 erofs: ensure that the post-EOF tails are all zeroed ARM: pxa: remove use of symbol_get() mmc: au1xmmc: force non-modular build and remove symbol_get usage rtc: ds1685: use EXPORT_SYMBOL_GPL for ds1685_rtc_poweroff modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules USB: serial: option: add Quectel EM05G variant (0x030e) USB: serial: option: add FOXCONN T99W368/T99W373 product HID: wacom: remove the battery when the EKR is off Bluetooth: btsdio: fix use after free bug in btsdio_remove due to race condition serial: sc16is7xx: fix bug when first setting GPIO direction fsi: master-ast-cf: Add MODULE_FIRMWARE macro nilfs2: fix general protection fault in nilfs_lookup_dirty_data_buffers() nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse pinctrl: amd: Don't show `Invalid config param` errors 9p: virtio: make sure 'offs' is initialized in zc_request ASoC: da7219: Flush pending AAD IRQ when suspending ASoC: da7219: Check for failure reading AAD IRQ events ethernet: atheros: fix return value check in atl1c_tso_csum() vxlan: generalize vxlan_parse_gpe_hdr and remove unused args m68k: Fix invalid .section syntax s390/dasd: use correct number of retries for ERP requests s390/dasd: fix hanging device after request requeue fs/nls: make load_nls() take a const parameter ASoc: codecs: ES8316: Fix DMIC config ASoC: atmel: Fix the 8K sample parameter in I2SC master platform/x86: intel: hid: Always call BTNL ACPI method security: keys: perform capable check only on privileged operations net: usb: qmi_wwan: add Quectel EM05GV2 idmaengine: make FSL_EDMA and INTEL_IDMA64 depends on HAS_IOMEM scsi: qedi: Fix potential deadlock on &qedi_percpu->p_work_lock netlabel: fix shift wrapping bug in netlbl_catmap_setlong() bnx2x: fix page fault following EEH recovery sctp: handle invalid error codes without calling BUG() cifs: add a warning when the in-flight count goes negative ALSA: seq: oss: Fix racy open/close of MIDI devices net: Avoid address overwrite in kernel_connect powerpc/32: Include .branch_lt in data section powerpc/32s: Fix assembler warning about r0 udf: Check consistency of Space Bitmap Descriptor udf: Handle error when adding extent to a file Revert "net: macsec: preserve ingress frame ordering" reiserfs: Check the return value from __getblk() eventfd: Export eventfd_ctx_do_read() eventfd: prevent underflow for eventfd semaphores new helper: lookup_positive_unlocked() netfilter: nft_flow_offload: fix underflow in flowtable reference counter netfilter: nf_tables: missing NFT_TRANS_PREPARE_ERROR in flowtable deactivatation fs: Fix error checking for d_hash_and_lookup() cpufreq: powernow-k8: Use related_cpus instead of cpus in driver.exit() bpf: Clear the probe_addr for uprobe tcp: tcp_enter_quickack_mode() should be static regmap: rbtree: Use alloc_flags for memory allocations spi: tegra20-sflash: fix to check return value of platform_get_irq() in tegra_sflash_probe() can: gs_usb: gs_usb_receive_bulk_callback(): count RX overflow errors also in case of OOM wifi: mwifiex: Fix OOB and integer underflow when rx packets mwifiex: drop 'set_consistent_dma_mask' log message mwifiex: switch from 'pci_' to 'dma_' API wifi: mwifiex: fix error recovery in PCIE buffer descriptor management Bluetooth: nokia: fix value check in nokia_bluetooth_serdev_probe() crypto: caam - fix unchecked return value error lwt: Check LWTUNNEL_XMIT_CONTINUE strictly fs: ocfs2: namei: check return value of ocfs2_add_entry() wifi: mwifiex: fix memory leak in mwifiex_histogram_read() wifi: mwifiex: Fix missed return in oob checks failed path wifi: ath9k: fix races between ath9k_wmi_cmd and ath9k_wmi_ctrl_rx wifi: ath9k: protect WMI command response buffer replacement with a lock wifi: mwifiex: avoid possible NULL skb pointer dereference wifi: ath9k: use IS_ERR() with debugfs_create_dir() net: arcnet: Do not call kfree_skb() under local_irq_disable() net/sched: sch_hfsc: Ensure inner classes have fsc curve netrom: Deny concurrent connect(). quota: add dqi_dirty_list description to comment of Dquot List Management quota: avoid increasing DQST_LOOKUPS when iterating over dirty/inuse list quota: factor out dquot_write_dquot() quota: rename dquot_active() to inode_quota_active() quota: add new helper dquot_active() quota: fix dqput() to follow the guarantees dquot_srcu should provide arm64: dts: msm8996: thermal: Add interrupt support arm64: dts: qcom: msm8996: Add missing interrupt to the USB2 controller drm/amdgpu: avoid integer overflow warning in amdgpu_device_resize_fb_bar() ARM: dts: BCM5301X: Harmonize EHCI/OHCI DT nodes name ARM: dts: BCM53573: Describe on-SoC BCM53125 rev 4 switch ARM: dts: BCM53573: Drop nonexistent #usb-cells ARM: dts: BCM53573: Add cells sizes to PCIe node ARM: dts: BCM53573: Use updated "spi-gpio" binding properties ARM: dts: s3c6410: move fixed clocks under root node in Mini6410 ARM: dts: s3c6410: align node SROM bus node name with dtschema in Mini6410 ARM: dts: s3c64xx: align pinctrl with dtschema ARM: dts: samsung: s3c6410-mini6410: correct ethernet reg addresses (split) ARM: dts: s5pv210: add RTC 32 KHz clock in SMDKV210 ARM: dts: s5pv210: use defines for IRQ flags in SMDKV210 ARM: dts: s5pv210: correct ethernet unit address in SMDKV210 ARM: dts: s5pv210: add dummy 5V regulator for backlight on SMDKv210 ARM: dts: samsung: s5pv210-smdkv210: correct ethernet reg addresses (split) drm: adv7511: Fix low refresh rate register for ADV7533/5 ARM: dts: BCM53573: Fix Ethernet info for Luxul devices drm/tegra: Remove superfluous error messages around platform_get_irq() drm/tegra: dpaux: Fix incorrect return value of platform_get_irq of: unittest: fix null pointer dereferencing in of_unittest_find_node_by_name() drm/msm: Replace drm_framebuffer_{un/reference} with put, get functions drm/msm/mdp5: Don't leak some plane state smackfs: Prevent underflow in smk_set_cipso() audit: fix possible soft lockup in __audit_inode_child() of: unittest: Fix overlay type in apply/revert check ALSA: ac97: Fix possible error value of *rac97 drivers: clk: keystone: Fix parameter judgment in _of_pll_clk_init() clk: sunxi-ng: Modify mismatched function name PCI: Mark NVIDIA T4 GPUs to avoid bus reset PCI: pciehp: Use RMW accessors for changing LNKCTL PCI/ASPM: Use RMW accessors for changing LNKCTL PCI/ATS: Add pci_prg_resp_pasid_required() interface. PCI: Cleanup register definition width and whitespace PCI: Decode PCIe 32 GT/s link speed PCI: Add #defines for Enter Compliance, Transmit Margin drm/amdgpu: Correct Transmit Margin masks drm/amdgpu: Replace numbers with PCI_EXP_LNKCTL2 definitions drm/amdgpu: Prefer pcie_capability_read_word() drm/amdgpu: Use RMW accessors for changing LNKCTL drm/radeon: Correct Transmit Margin masks drm/radeon: Replace numbers with PCI_EXP_LNKCTL2 definitions drm/radeon: Prefer pcie_capability_read_word() drm/radeon: Use RMW accessors for changing LNKCTL wifi: ath10k: Use RMW accessors for changing LNKCTL nfs/blocklayout: Use the passed in gfp flags powerpc/iommu: Fix notifiers being shared by PCI and VIO buses jfs: validate max amount of blocks before allocation. fs: lockd: avoid possible wrong NULL parameter NFSD: da_addr_body field missing in some GETDEVICEINFO replies media: Use of_node_name_eq for node name comparisons media: v4l2-fwnode: fix v4l2_fwnode_parse_link handling media: v4l2-fwnode: simplify v4l2_fwnode_parse_link media: v4l2-core: Fix a potential resource leak in v4l2_fwnode_parse_link() drivers: usb: smsusb: fix error handling code in smsusb_init_device media: dib7000p: Fix potential division by zero media: dvb-usb: m920x: Fix a potential memory leak in m920x_i2c_xfer() media: cx24120: Add retval check for cx24120_message_send() media: mediatek: vcodec: Return NULL if no vdec_fb is found usb: phy: mxs: fix getting wrong state with mxs_phy_is_otg_host() scsi: iscsi: Add strlen() check in iscsi_if_set{_host}_param() scsi: be2iscsi: Add length check when parsing nlattrs scsi: qla4xxx: Add length check when parsing nlattrs x86/APM: drop the duplicate APM_MINOR_DEV macro scsi: qedf: Do not touch __user pointer in qedf_dbg_stop_io_on_error_cmd_read() directly scsi: qedf: Do not touch __user pointer in qedf_dbg_fp_int_cmd_read() directly dma-buf/sync_file: Fix docs syntax IB/uverbs: Fix an potential error pointer dereference media: go7007: Remove redundant if statement USB: gadget: f_mass_storage: Fix unused variable warning media: i2c: ov2680: Set V4L2_CTRL_FLAG_MODIFY_LAYOUT on flips media: ov2680: Remove auto-gain and auto-exposure controls media: ov2680: Fix ov2680_bayer_order() media: ov2680: Fix vflip / hflip set functions media: ov2680: Fix regulators being left enabled on ov2680_power_on() errors cgroup:namespace: Remove unused cgroup_namespaces_init() scsi: core: Use 32-bit hostnum in scsi_host_lookup() scsi: fcoe: Fix potential deadlock on &fip->ctlr_lock serial: tegra: handle clk prepare error in tegra_uart_hw_init() amba: bus: fix refcount leak Revert "IB/isert: Fix incorrect release of isert connection" HID: multitouch: Correct devm device reference for hidinput input_dev name rpmsg: glink: Add check for kstrdup arch: um: drivers: Kconfig: pedantic formatting um: Fix hostaudio build errors dmaengine: ste_dma40: Add missing IRQ check in d40_probe igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU netfilter: ipset: add the missing IP_SET_HASH_WITH_NET0 macro for ip_set_hash_netportnet.c netfilter: xt_u32: validate user space input netfilter: xt_sctp: validate the flag_info count skbuff: skb_segment, Call zero copy functions before using skbuff frags igb: set max size RX buffer when store bad packet is enabled PM / devfreq: Fix leak in devfreq_dev_release() ALSA: pcm: Fix missing fixup call in compat hw_refine ioctl ipmi_si: fix a memleak in try_smi_init() ARM: OMAP2+: Fix -Warray-bounds warning in _pwrdm_state_switch() backlight/gpio_backlight: Compare against struct fb_info.device backlight/bd6107: Compare against struct fb_info.device backlight/lv5207lp: Compare against struct fb_info.device media: dvb: symbol fixup for dvb_attach() ntb: Drop packets when qp link is down ntb: Clean up tx tail index on link down ntb: Fix calculation ntb_transport_tx_free_entry() Revert "PCI: Mark NVIDIA T4 GPUs to avoid bus reset" procfs: block chmod on /proc/thread-self/comm parisc: Fix /proc/cpuinfo output for lscpu dlm: fix plock lookup when using multiple lockspaces dccp: Fix out of bounds access in DCCP error handler crypto: stm32 - fix loop iterating through scatterlist for DMA cpufreq: brcmstb-avs-cpufreq: Fix -Warray-bounds bug X.509: if signature is unsupported skip validation net: handle ARPHRD_PPP in dev_is_mac_header_xmit() pstore/ram: Check start of empty przs during init PCI/ATS: Add inline to pci_prg_resp_pasid_required() sc16is7xx: Set iobase to device index serial: sc16is7xx: fix broken port 0 uart init usb: typec: tcpci: clear the fault status bit udf: initialize newblock to 0 scsi: qla2xxx: fix inconsistent TMF timeout scsi: qla2xxx: Turn off noisy message log fbdev/ep93xx-fb: Do not assign to struct fb_info.dev drm/ast: Fix DRAM init on AST2200 parisc: led: Fix LAN receive and transmit LEDs parisc: led: Reduce CPU overhead for disk & lan LED computation clk: qcom: gcc-mdm9615: use proper parent for pll0_vote clock soc: qcom: qmi_encdec: Restrict string length in decode NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info kconfig: fix possible buffer overflow x86/virt: Drop unnecessary check on extended CPUID level in cpu_has_svm() watchdog: intel-mid_wdt: add MODULE_ALIAS() to allow auto-load pwm: lpc32xx: Remove handling of PWM channels net: read sk->sk_family once in sk_mc_loop() igb: disable virtualization features on 82580 veth: Fixing transmit return status for dropped packets net: ipv6/addrconf: avoid integer underflow in ipv6_create_tempaddr af_unix: Fix data-races around user->unix_inflight. af_unix: Fix data-race around unix_tot_inflight. af_unix: Fix data-races around sk->sk_shutdown. af_unix: Fix data race around sk->sk_err. net: sched: sch_qfq: Fix UAF in qfq_dequeue() kcm: Destroy mutex in kcm_exit_net() igbvf: Change IGBVF_MIN to allow set rx/tx value between 64 and 80 igb: Change IGB_MIN to allow set rx/tx value between 64 and 80 idr: fix param name in idr_alloc_cyclic() doc netfilter: nfnetlink_osf: avoid OOB read ata: sata_gemini: Add missing MODULE_DESCRIPTION ata: pata_ftide010: Add missing MODULE_DESCRIPTION btrfs: don't start transaction when joining with TRANS_JOIN_NOSTART mtd: rawnand: brcmnand: Fix crash during the panic_write mtd: rawnand: brcmnand: Fix potential out-of-bounds access in oob write mtd: rawnand: brcmnand: Fix potential false time out warning perf hists browser: Fix hierarchy mode header net: ethernet: mtk_eth_soc: fix possible NULL pointer dereference in mtk_hwlro_get_fdir_all() kcm: Fix memory leak in error path of kcm_sendmsg() ixgbe: fix timestamp configuration code kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg(). drm/amd/display: Fix a bug when searching for insert_above_mpcc parisc: Drop loops_per_jiffy from per_cpu struct autofs: fix memory leak of waitqueues in autofs_catatonic_mode btrfs: output extra debug info if we failed to find an inline backref ACPICA: Add AML_NO_OPERAND_RESOLVE flag to Timer ACPI: video: Add backlight=native DMI quirk for Lenovo Ideapad Z470 hw_breakpoint: fix single-stepping when using bpf_overflow_handler wifi: ath9k: fix printk specifier wifi: mwifiex: fix fortify warning crypto: lib/mpi - avoid null pointer deref in mpi_cmp_ui() tpm_tis: Resend command to recover from data transfer errors alx: fix OOB-read compiler warning drm/exynos: fix a possible null-pointer dereference due to data race in exynos_drm_crtc_atomic_disable() md: raid1: fix potential OOB in raid1_remove_disk() ext2: fix datatype of block number in ext2_xattr_set2() fs/jfs: prevent double-free in dbUnmount() after failed jfs_remount() jfs: fix invalid free of JFS_IP(ipimap)->i_imap in diUnmount powerpc/pseries: fix possible memory leak in ibmebus_bus_init() media: dvb-usb-v2: af9035: Fix null-ptr-deref in af9035_i2c_master_xfer media: dw2102: Fix null-ptr-deref in dw2102_i2c_transfer() media: af9005: Fix null-ptr-deref in af9005_i2c_xfer media: anysee: fix null-ptr-deref in anysee_master_xfer media: az6007: Fix null-ptr-deref in az6007_i2c_xfer() iio: core: Use min() instead of min_t() to make code more robust media: tuners: qt1010: replace BUG_ON with a regular error media: pci: cx23885: replace BUG with error return usb: gadget: fsl_qe_udc: validate endpoint index for ch9 udc scsi: target: iscsi: Fix buffer overflow in lio_target_nacl_info_show() serial: cpm_uart: Avoid suspicious locking media: pci: ipu3-cio2: Initialise timing struct to avoid a compiler warning kobject: Add sanity check for kset->kobj.ktype in kset_register() md/raid1: fix error: ISO C90 forbids mixed declarations attr: block mode changes of symlinks btrfs: fix lockdep splat and potential deadlock after failure running delayed items nfsd: fix change_info in NFSv4 RENAME replies mtd: rawnand: brcmnand: Fix ECC level field setting for v7.2 controller net/sched: cls_fw: No longer copy tcf_result on update to avoid use-after-free net/sched: Retire rsvp classifier Linux 4.19.295 Change-Id: I5de88dc1e8cebe5736df3023205233cb40c4aa35 Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
1158 lines
27 KiB
C
1158 lines
27 KiB
C
/*
|
|
* Copyright (C) 2011 Novell Inc.
|
|
* Copyright (C) 2016 Red Hat, Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 as published by
|
|
* the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/cred.h>
|
|
#include <linux/ctype.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/xattr.h>
|
|
#include <linux/ratelimit.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/exportfs.h>
|
|
#include "overlayfs.h"
|
|
|
|
struct ovl_lookup_data {
|
|
struct super_block *sb;
|
|
struct qstr name;
|
|
bool is_dir;
|
|
bool opaque;
|
|
bool stop;
|
|
bool last;
|
|
char *redirect;
|
|
bool metacopy;
|
|
};
|
|
|
|
static int ovl_check_redirect(struct dentry *dentry, struct ovl_lookup_data *d,
|
|
size_t prelen, const char *post)
|
|
{
|
|
int res;
|
|
char *buf;
|
|
|
|
buf = ovl_get_redirect_xattr(dentry, prelen + strlen(post));
|
|
if (IS_ERR_OR_NULL(buf))
|
|
return PTR_ERR(buf);
|
|
|
|
if (buf[0] == '/') {
|
|
/*
|
|
* One of the ancestor path elements in an absolute path
|
|
* lookup in ovl_lookup_layer() could have been opaque and
|
|
* that will stop further lookup in lower layers (d->stop=true)
|
|
* But we have found an absolute redirect in decendant path
|
|
* element and that should force continue lookup in lower
|
|
* layers (reset d->stop).
|
|
*/
|
|
d->stop = false;
|
|
} else {
|
|
res = strlen(buf) + 1;
|
|
memmove(buf + prelen, buf, res);
|
|
memcpy(buf, d->name.name, prelen);
|
|
}
|
|
|
|
strcat(buf, post);
|
|
kfree(d->redirect);
|
|
d->redirect = buf;
|
|
d->name.name = d->redirect;
|
|
d->name.len = strlen(d->redirect);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ovl_acceptable(void *ctx, struct dentry *dentry)
|
|
{
|
|
/*
|
|
* A non-dir origin may be disconnected, which is fine, because
|
|
* we only need it for its unique inode number.
|
|
*/
|
|
if (!d_is_dir(dentry))
|
|
return 1;
|
|
|
|
/* Don't decode a deleted empty directory */
|
|
if (d_unhashed(dentry))
|
|
return 0;
|
|
|
|
/* Check if directory belongs to the layer we are decoding from */
|
|
return is_subdir(dentry, ((struct vfsmount *)ctx)->mnt_root);
|
|
}
|
|
|
|
/*
|
|
* Check validity of an overlay file handle buffer.
|
|
*
|
|
* Return 0 for a valid file handle.
|
|
* Return -ENODATA for "origin unknown".
|
|
* Return <0 for an invalid file handle.
|
|
*/
|
|
int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
|
|
{
|
|
if (fh_len < sizeof(struct ovl_fh) || fh_len < fh->len)
|
|
return -EINVAL;
|
|
|
|
if (fh->magic != OVL_FH_MAGIC)
|
|
return -EINVAL;
|
|
|
|
/* Treat larger version and unknown flags as "origin unknown" */
|
|
if (fh->version > OVL_FH_VERSION || fh->flags & ~OVL_FH_FLAG_ALL)
|
|
return -ENODATA;
|
|
|
|
/* Treat endianness mismatch as "origin unknown" */
|
|
if (!(fh->flags & OVL_FH_FLAG_ANY_ENDIAN) &&
|
|
(fh->flags & OVL_FH_FLAG_BIG_ENDIAN) != OVL_FH_FLAG_CPU_ENDIAN)
|
|
return -ENODATA;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name)
|
|
{
|
|
ssize_t res;
|
|
int err;
|
|
struct ovl_fh *fh = NULL;
|
|
|
|
res = ovl_vfs_getxattr(dentry, name, NULL, 0);
|
|
if (res < 0) {
|
|
if (res == -ENODATA || res == -EOPNOTSUPP)
|
|
return NULL;
|
|
goto fail;
|
|
}
|
|
/* Zero size value means "copied up but origin unknown" */
|
|
if (res == 0)
|
|
return NULL;
|
|
|
|
fh = kzalloc(res, GFP_KERNEL);
|
|
if (!fh)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
res = ovl_vfs_getxattr(dentry, name, fh, res);
|
|
if (res < 0)
|
|
goto fail;
|
|
|
|
err = ovl_check_fh_len(fh, res);
|
|
if (err < 0) {
|
|
if (err == -ENODATA)
|
|
goto out;
|
|
goto invalid;
|
|
}
|
|
|
|
return fh;
|
|
|
|
out:
|
|
kfree(fh);
|
|
return NULL;
|
|
|
|
fail:
|
|
pr_warn_ratelimited("overlayfs: failed to get origin (%zi)\n", res);
|
|
goto out;
|
|
invalid:
|
|
pr_warn_ratelimited("overlayfs: invalid origin (%*phN)\n",
|
|
(int)res, fh);
|
|
goto out;
|
|
}
|
|
|
|
struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
|
|
bool connected)
|
|
{
|
|
struct dentry *real;
|
|
int bytes;
|
|
|
|
/*
|
|
* Make sure that the stored uuid matches the uuid of the lower
|
|
* layer where file handle will be decoded.
|
|
*/
|
|
if (!uuid_equal(&fh->uuid, &mnt->mnt_sb->s_uuid))
|
|
return NULL;
|
|
|
|
bytes = (fh->len - offsetof(struct ovl_fh, fid));
|
|
real = exportfs_decode_fh(mnt, (struct fid *)fh->fid,
|
|
bytes >> 2, (int)fh->type,
|
|
connected ? ovl_acceptable : NULL, mnt);
|
|
if (IS_ERR(real)) {
|
|
/*
|
|
* Treat stale file handle to lower file as "origin unknown".
|
|
* upper file handle could become stale when upper file is
|
|
* unlinked and this information is needed to handle stale
|
|
* index entries correctly.
|
|
*/
|
|
if (real == ERR_PTR(-ESTALE) &&
|
|
!(fh->flags & OVL_FH_FLAG_PATH_UPPER))
|
|
real = NULL;
|
|
return real;
|
|
}
|
|
|
|
if (ovl_dentry_weird(real)) {
|
|
dput(real);
|
|
return NULL;
|
|
}
|
|
|
|
return real;
|
|
}
|
|
|
|
static bool ovl_is_opaquedir(struct dentry *dentry)
|
|
{
|
|
return ovl_check_dir_xattr(dentry, OVL_XATTR_OPAQUE);
|
|
}
|
|
|
|
static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
|
|
const char *name, unsigned int namelen,
|
|
size_t prelen, const char *post,
|
|
struct dentry **ret)
|
|
{
|
|
struct dentry *this;
|
|
int err;
|
|
bool last_element = !post[0];
|
|
|
|
this = lookup_positive_unlocked(name, base, namelen);
|
|
if (IS_ERR(this)) {
|
|
err = PTR_ERR(this);
|
|
this = NULL;
|
|
if (err == -ENOENT || err == -ENAMETOOLONG)
|
|
goto out;
|
|
goto out_err;
|
|
}
|
|
|
|
if (ovl_dentry_weird(this)) {
|
|
/* Don't support traversing automounts and other weirdness */
|
|
err = -EREMOTE;
|
|
goto out_err;
|
|
}
|
|
if (ovl_is_whiteout(this)) {
|
|
d->stop = d->opaque = true;
|
|
goto put_and_out;
|
|
}
|
|
/*
|
|
* This dentry should be a regular file if previous layer lookup
|
|
* found a metacopy dentry.
|
|
*/
|
|
if (last_element && d->metacopy && !d_is_reg(this)) {
|
|
d->stop = true;
|
|
goto put_and_out;
|
|
}
|
|
if (!d_can_lookup(this)) {
|
|
if (d->is_dir || !last_element) {
|
|
d->stop = true;
|
|
goto put_and_out;
|
|
}
|
|
err = ovl_check_metacopy_xattr(this);
|
|
if (err < 0)
|
|
goto out_err;
|
|
|
|
d->metacopy = err;
|
|
d->stop = !d->metacopy;
|
|
if (!d->metacopy || d->last)
|
|
goto out;
|
|
} else {
|
|
if (ovl_lookup_trap_inode(d->sb, this)) {
|
|
/* Caught in a trap of overlapping layers */
|
|
err = -ELOOP;
|
|
goto out_err;
|
|
}
|
|
|
|
if (last_element)
|
|
d->is_dir = true;
|
|
if (d->last)
|
|
goto out;
|
|
|
|
if (ovl_is_opaquedir(this)) {
|
|
d->stop = true;
|
|
if (last_element)
|
|
d->opaque = true;
|
|
goto out;
|
|
}
|
|
}
|
|
err = ovl_check_redirect(this, d, prelen, post);
|
|
if (err)
|
|
goto out_err;
|
|
out:
|
|
*ret = this;
|
|
return 0;
|
|
|
|
put_and_out:
|
|
dput(this);
|
|
this = NULL;
|
|
goto out;
|
|
|
|
out_err:
|
|
dput(this);
|
|
return err;
|
|
}
|
|
|
|
static int ovl_lookup_layer(struct dentry *base, struct ovl_lookup_data *d,
|
|
struct dentry **ret)
|
|
{
|
|
/* Counting down from the end, since the prefix can change */
|
|
size_t rem = d->name.len - 1;
|
|
struct dentry *dentry = NULL;
|
|
int err;
|
|
|
|
if (d->name.name[0] != '/')
|
|
return ovl_lookup_single(base, d, d->name.name, d->name.len,
|
|
0, "", ret);
|
|
|
|
while (!IS_ERR_OR_NULL(base) && d_can_lookup(base)) {
|
|
const char *s = d->name.name + d->name.len - rem;
|
|
const char *next = strchrnul(s, '/');
|
|
size_t thislen = next - s;
|
|
bool end = !next[0];
|
|
|
|
/* Verify we did not go off the rails */
|
|
if (WARN_ON(s[-1] != '/'))
|
|
return -EIO;
|
|
|
|
err = ovl_lookup_single(base, d, s, thislen,
|
|
d->name.len - rem, next, &base);
|
|
dput(dentry);
|
|
if (err)
|
|
return err;
|
|
dentry = base;
|
|
if (end)
|
|
break;
|
|
|
|
rem -= thislen + 1;
|
|
|
|
if (WARN_ON(rem >= d->name.len))
|
|
return -EIO;
|
|
}
|
|
*ret = dentry;
|
|
return 0;
|
|
}
|
|
|
|
|
|
int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
|
|
struct dentry *upperdentry, struct ovl_path **stackp)
|
|
{
|
|
struct dentry *origin = NULL;
|
|
int i;
|
|
|
|
for (i = 0; i < ofs->numlower; i++) {
|
|
origin = ovl_decode_real_fh(fh, ofs->lower_layers[i].mnt,
|
|
connected);
|
|
if (origin)
|
|
break;
|
|
}
|
|
|
|
if (!origin)
|
|
return -ESTALE;
|
|
else if (IS_ERR(origin))
|
|
return PTR_ERR(origin);
|
|
|
|
if (upperdentry && !ovl_is_whiteout(upperdentry) &&
|
|
((d_inode(origin)->i_mode ^ d_inode(upperdentry)->i_mode) & S_IFMT))
|
|
goto invalid;
|
|
|
|
if (!*stackp)
|
|
*stackp = kmalloc(sizeof(struct ovl_path), GFP_KERNEL);
|
|
if (!*stackp) {
|
|
dput(origin);
|
|
return -ENOMEM;
|
|
}
|
|
**stackp = (struct ovl_path){
|
|
.dentry = origin,
|
|
.layer = &ofs->lower_layers[i]
|
|
};
|
|
|
|
return 0;
|
|
|
|
invalid:
|
|
pr_warn_ratelimited("overlayfs: invalid origin (%pd2, ftype=%x, origin ftype=%x).\n",
|
|
upperdentry, d_inode(upperdentry)->i_mode & S_IFMT,
|
|
d_inode(origin)->i_mode & S_IFMT);
|
|
dput(origin);
|
|
return -EIO;
|
|
}
|
|
|
|
static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,
|
|
struct ovl_path **stackp, unsigned int *ctrp)
|
|
{
|
|
struct ovl_fh *fh = ovl_get_fh(upperdentry, OVL_XATTR_ORIGIN);
|
|
int err;
|
|
|
|
if (IS_ERR_OR_NULL(fh))
|
|
return PTR_ERR(fh);
|
|
|
|
err = ovl_check_origin_fh(ofs, fh, false, upperdentry, stackp);
|
|
kfree(fh);
|
|
|
|
if (err) {
|
|
if (err == -ESTALE)
|
|
return 0;
|
|
return err;
|
|
}
|
|
|
|
if (WARN_ON(*ctrp))
|
|
return -EIO;
|
|
|
|
*ctrp = 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Verify that @fh matches the file handle stored in xattr @name.
|
|
* Return 0 on match, -ESTALE on mismatch, < 0 on error.
|
|
*/
|
|
static int ovl_verify_fh(struct dentry *dentry, const char *name,
|
|
const struct ovl_fh *fh)
|
|
{
|
|
struct ovl_fh *ofh = ovl_get_fh(dentry, name);
|
|
int err = 0;
|
|
|
|
if (!ofh)
|
|
return -ENODATA;
|
|
|
|
if (IS_ERR(ofh))
|
|
return PTR_ERR(ofh);
|
|
|
|
if (fh->len != ofh->len || memcmp(fh, ofh, fh->len))
|
|
err = -ESTALE;
|
|
|
|
kfree(ofh);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Verify that @real dentry matches the file handle stored in xattr @name.
|
|
*
|
|
* If @set is true and there is no stored file handle, encode @real and store
|
|
* file handle in xattr @name.
|
|
*
|
|
* Return 0 on match, -ESTALE on mismatch, -ENODATA on no xattr, < 0 on error.
|
|
*/
|
|
int ovl_verify_set_fh(struct dentry *dentry, const char *name,
|
|
struct dentry *real, bool is_upper, bool set)
|
|
{
|
|
struct inode *inode;
|
|
struct ovl_fh *fh;
|
|
int err;
|
|
|
|
fh = ovl_encode_real_fh(real, is_upper);
|
|
err = PTR_ERR(fh);
|
|
if (IS_ERR(fh)) {
|
|
fh = NULL;
|
|
goto fail;
|
|
}
|
|
|
|
err = ovl_verify_fh(dentry, name, fh);
|
|
if (set && err == -ENODATA)
|
|
err = ovl_do_setxattr(dentry, name, fh, fh->len, 0);
|
|
if (err)
|
|
goto fail;
|
|
|
|
out:
|
|
kfree(fh);
|
|
return err;
|
|
|
|
fail:
|
|
inode = d_inode(real);
|
|
pr_warn_ratelimited("overlayfs: failed to verify %s (%pd2, ino=%lu, err=%i)\n",
|
|
is_upper ? "upper" : "origin", real,
|
|
inode ? inode->i_ino : 0, err);
|
|
goto out;
|
|
}
|
|
|
|
/* Get upper dentry from index */
|
|
struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index)
|
|
{
|
|
struct ovl_fh *fh;
|
|
struct dentry *upper;
|
|
|
|
if (!d_is_dir(index))
|
|
return dget(index);
|
|
|
|
fh = ovl_get_fh(index, OVL_XATTR_UPPER);
|
|
if (IS_ERR_OR_NULL(fh))
|
|
return ERR_CAST(fh);
|
|
|
|
upper = ovl_decode_real_fh(fh, ofs->upper_mnt, true);
|
|
kfree(fh);
|
|
|
|
if (IS_ERR_OR_NULL(upper))
|
|
return upper ?: ERR_PTR(-ESTALE);
|
|
|
|
if (!d_is_dir(upper)) {
|
|
pr_warn_ratelimited("overlayfs: invalid index upper (%pd2, upper=%pd2).\n",
|
|
index, upper);
|
|
dput(upper);
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
|
|
return upper;
|
|
}
|
|
|
|
/* Is this a leftover from create/whiteout of directory index entry? */
|
|
static bool ovl_is_temp_index(struct dentry *index)
|
|
{
|
|
return index->d_name.name[0] == '#';
|
|
}
|
|
|
|
/*
|
|
* Verify that an index entry name matches the origin file handle stored in
|
|
* OVL_XATTR_ORIGIN and that origin file handle can be decoded to lower path.
|
|
* Return 0 on match, -ESTALE on mismatch or stale origin, < 0 on error.
|
|
*/
|
|
int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index)
|
|
{
|
|
struct ovl_fh *fh = NULL;
|
|
size_t len;
|
|
struct ovl_path origin = { };
|
|
struct ovl_path *stack = &origin;
|
|
struct dentry *upper = NULL;
|
|
int err;
|
|
|
|
if (!d_inode(index))
|
|
return 0;
|
|
|
|
/* Cleanup leftover from index create/cleanup attempt */
|
|
err = -ESTALE;
|
|
if (ovl_is_temp_index(index))
|
|
goto fail;
|
|
|
|
err = -EINVAL;
|
|
if (index->d_name.len < sizeof(struct ovl_fh)*2)
|
|
goto fail;
|
|
|
|
err = -ENOMEM;
|
|
len = index->d_name.len / 2;
|
|
fh = kzalloc(len, GFP_KERNEL);
|
|
if (!fh)
|
|
goto fail;
|
|
|
|
err = -EINVAL;
|
|
if (hex2bin((u8 *)fh, index->d_name.name, len))
|
|
goto fail;
|
|
|
|
err = ovl_check_fh_len(fh, len);
|
|
if (err)
|
|
goto fail;
|
|
|
|
/*
|
|
* Whiteout index entries are used as an indication that an exported
|
|
* overlay file handle should be treated as stale (i.e. after unlink
|
|
* of the overlay inode). These entries contain no origin xattr.
|
|
*/
|
|
if (ovl_is_whiteout(index))
|
|
goto out;
|
|
|
|
/*
|
|
* Verifying directory index entries are not stale is expensive, so
|
|
* only verify stale dir index if NFS export is enabled.
|
|
*/
|
|
if (d_is_dir(index) && !ofs->config.nfs_export)
|
|
goto out;
|
|
|
|
/*
|
|
* Directory index entries should have 'upper' xattr pointing to the
|
|
* real upper dir. Non-dir index entries are hardlinks to the upper
|
|
* real inode. For non-dir index, we can read the copy up origin xattr
|
|
* directly from the index dentry, but for dir index we first need to
|
|
* decode the upper directory.
|
|
*/
|
|
upper = ovl_index_upper(ofs, index);
|
|
if (IS_ERR_OR_NULL(upper)) {
|
|
err = PTR_ERR(upper);
|
|
/*
|
|
* Directory index entries with no 'upper' xattr need to be
|
|
* removed. When dir index entry has a stale 'upper' xattr,
|
|
* we assume that upper dir was removed and we treat the dir
|
|
* index as orphan entry that needs to be whited out.
|
|
*/
|
|
if (err == -ESTALE)
|
|
goto orphan;
|
|
else if (!err)
|
|
err = -ESTALE;
|
|
goto fail;
|
|
}
|
|
|
|
err = ovl_verify_fh(upper, OVL_XATTR_ORIGIN, fh);
|
|
dput(upper);
|
|
if (err)
|
|
goto fail;
|
|
|
|
/* Check if non-dir index is orphan and don't warn before cleaning it */
|
|
if (!d_is_dir(index) && d_inode(index)->i_nlink == 1) {
|
|
err = ovl_check_origin_fh(ofs, fh, false, index, &stack);
|
|
if (err)
|
|
goto fail;
|
|
|
|
if (ovl_get_nlink(origin.dentry, index, 0) == 0)
|
|
goto orphan;
|
|
}
|
|
|
|
out:
|
|
dput(origin.dentry);
|
|
kfree(fh);
|
|
return err;
|
|
|
|
fail:
|
|
pr_warn_ratelimited("overlayfs: failed to verify index (%pd2, ftype=%x, err=%i)\n",
|
|
index, d_inode(index)->i_mode & S_IFMT, err);
|
|
goto out;
|
|
|
|
orphan:
|
|
pr_warn_ratelimited("overlayfs: orphan index entry (%pd2, ftype=%x, nlink=%u)\n",
|
|
index, d_inode(index)->i_mode & S_IFMT,
|
|
d_inode(index)->i_nlink);
|
|
err = -ENOENT;
|
|
goto out;
|
|
}
|
|
|
|
static int ovl_get_index_name_fh(struct ovl_fh *fh, struct qstr *name)
|
|
{
|
|
char *n, *s;
|
|
|
|
n = kcalloc(fh->len, 2, GFP_KERNEL);
|
|
if (!n)
|
|
return -ENOMEM;
|
|
|
|
s = bin2hex(n, fh, fh->len);
|
|
*name = (struct qstr) QSTR_INIT(n, s - n);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
/*
|
|
* Lookup in indexdir for the index entry of a lower real inode or a copy up
|
|
* origin inode. The index entry name is the hex representation of the lower
|
|
* inode file handle.
|
|
*
|
|
* If the index dentry in negative, then either no lower aliases have been
|
|
* copied up yet, or aliases have been copied up in older kernels and are
|
|
* not indexed.
|
|
*
|
|
* If the index dentry for a copy up origin inode is positive, but points
|
|
* to an inode different than the upper inode, then either the upper inode
|
|
* has been copied up and not indexed or it was indexed, but since then
|
|
* index dir was cleared. Either way, that index cannot be used to indentify
|
|
* the overlay inode.
|
|
*/
|
|
int ovl_get_index_name(struct dentry *origin, struct qstr *name)
|
|
{
|
|
struct ovl_fh *fh;
|
|
int err;
|
|
|
|
fh = ovl_encode_real_fh(origin, false);
|
|
if (IS_ERR(fh))
|
|
return PTR_ERR(fh);
|
|
|
|
err = ovl_get_index_name_fh(fh, name);
|
|
|
|
kfree(fh);
|
|
return err;
|
|
}
|
|
|
|
/* Lookup index by file handle for NFS export */
|
|
struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh)
|
|
{
|
|
struct dentry *index;
|
|
struct qstr name;
|
|
int err;
|
|
|
|
err = ovl_get_index_name_fh(fh, &name);
|
|
if (err)
|
|
return ERR_PTR(err);
|
|
|
|
index = lookup_positive_unlocked(name.name, ofs->indexdir, name.len);
|
|
kfree(name.name);
|
|
if (IS_ERR(index)) {
|
|
if (PTR_ERR(index) == -ENOENT)
|
|
index = NULL;
|
|
return index;
|
|
}
|
|
|
|
if (ovl_is_whiteout(index))
|
|
err = -ESTALE;
|
|
else if (ovl_dentry_weird(index))
|
|
err = -EIO;
|
|
else
|
|
return index;
|
|
|
|
dput(index);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
|
|
struct dentry *origin, bool verify)
|
|
{
|
|
struct dentry *index;
|
|
struct inode *inode;
|
|
struct qstr name;
|
|
bool is_dir = d_is_dir(origin);
|
|
int err;
|
|
|
|
err = ovl_get_index_name(origin, &name);
|
|
if (err)
|
|
return ERR_PTR(err);
|
|
|
|
index = lookup_positive_unlocked(name.name, ofs->indexdir, name.len);
|
|
if (IS_ERR(index)) {
|
|
err = PTR_ERR(index);
|
|
if (err == -ENOENT) {
|
|
index = NULL;
|
|
goto out;
|
|
}
|
|
pr_warn_ratelimited("overlayfs: failed inode index lookup (ino=%lu, key=%.*s, err=%i);\n"
|
|
"overlayfs: mount with '-o index=off' to disable inodes index.\n",
|
|
d_inode(origin)->i_ino, name.len, name.name,
|
|
err);
|
|
goto out;
|
|
}
|
|
|
|
inode = d_inode(index);
|
|
if (ovl_is_whiteout(index) && !verify) {
|
|
/*
|
|
* When index lookup is called with !verify for decoding an
|
|
* overlay file handle, a whiteout index implies that decode
|
|
* should treat file handle as stale and no need to print a
|
|
* warning about it.
|
|
*/
|
|
dput(index);
|
|
index = ERR_PTR(-ESTALE);
|
|
goto out;
|
|
} else if (ovl_dentry_weird(index) || ovl_is_whiteout(index) ||
|
|
((inode->i_mode ^ d_inode(origin)->i_mode) & S_IFMT)) {
|
|
/*
|
|
* Index should always be of the same file type as origin
|
|
* except for the case of a whiteout index. A whiteout
|
|
* index should only exist if all lower aliases have been
|
|
* unlinked, which means that finding a lower origin on lookup
|
|
* whose index is a whiteout should be treated as an error.
|
|
*/
|
|
pr_warn_ratelimited("overlayfs: bad index found (index=%pd2, ftype=%x, origin ftype=%x).\n",
|
|
index, d_inode(index)->i_mode & S_IFMT,
|
|
d_inode(origin)->i_mode & S_IFMT);
|
|
goto fail;
|
|
} else if (is_dir && verify) {
|
|
if (!upper) {
|
|
pr_warn_ratelimited("overlayfs: suspected uncovered redirected dir found (origin=%pd2, index=%pd2).\n",
|
|
origin, index);
|
|
goto fail;
|
|
}
|
|
|
|
/* Verify that dir index 'upper' xattr points to upper dir */
|
|
err = ovl_verify_upper(index, upper, false);
|
|
if (err) {
|
|
if (err == -ESTALE) {
|
|
pr_warn_ratelimited("overlayfs: suspected multiply redirected dir found (upper=%pd2, origin=%pd2, index=%pd2).\n",
|
|
upper, origin, index);
|
|
}
|
|
goto fail;
|
|
}
|
|
} else if (upper && d_inode(upper) != inode) {
|
|
goto out_dput;
|
|
}
|
|
out:
|
|
kfree(name.name);
|
|
return index;
|
|
|
|
out_dput:
|
|
dput(index);
|
|
index = NULL;
|
|
goto out;
|
|
|
|
fail:
|
|
dput(index);
|
|
index = ERR_PTR(-EIO);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Returns next layer in stack starting from top.
|
|
* Returns -1 if this is the last layer.
|
|
*/
|
|
int ovl_path_next(int idx, struct dentry *dentry, struct path *path)
|
|
{
|
|
struct ovl_entry *oe = dentry->d_fsdata;
|
|
|
|
BUG_ON(idx < 0);
|
|
if (idx == 0) {
|
|
ovl_path_upper(dentry, path);
|
|
if (path->dentry)
|
|
return oe->numlower ? 1 : -1;
|
|
idx++;
|
|
}
|
|
BUG_ON(idx > oe->numlower);
|
|
path->dentry = oe->lowerstack[idx - 1].dentry;
|
|
path->mnt = oe->lowerstack[idx - 1].layer->mnt;
|
|
|
|
return (idx < oe->numlower) ? idx + 1 : -1;
|
|
}
|
|
|
|
/* Fix missing 'origin' xattr */
|
|
static int ovl_fix_origin(struct dentry *dentry, struct dentry *lower,
|
|
struct dentry *upper)
|
|
{
|
|
int err;
|
|
|
|
if (ovl_check_origin_xattr(upper))
|
|
return 0;
|
|
|
|
err = ovl_want_write(dentry);
|
|
if (err)
|
|
return err;
|
|
|
|
err = ovl_set_origin(dentry, lower, upper);
|
|
if (!err)
|
|
err = ovl_set_impure(dentry->d_parent, upper->d_parent);
|
|
|
|
ovl_drop_write(dentry);
|
|
return err;
|
|
}
|
|
|
|
struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
|
|
unsigned int flags)
|
|
{
|
|
struct ovl_entry *oe;
|
|
const struct cred *old_cred;
|
|
struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
|
|
struct ovl_entry *poe = dentry->d_parent->d_fsdata;
|
|
struct ovl_entry *roe = dentry->d_sb->s_root->d_fsdata;
|
|
struct ovl_path *stack = NULL, *origin_path = NULL;
|
|
struct dentry *upperdir, *upperdentry = NULL;
|
|
struct dentry *origin = NULL;
|
|
struct dentry *index = NULL;
|
|
unsigned int ctr = 0;
|
|
struct inode *inode = NULL;
|
|
bool upperopaque = false;
|
|
char *upperredirect = NULL;
|
|
struct dentry *this;
|
|
unsigned int i;
|
|
int err;
|
|
bool metacopy = false;
|
|
struct ovl_lookup_data d = {
|
|
.sb = dentry->d_sb,
|
|
.name = dentry->d_name,
|
|
.is_dir = false,
|
|
.opaque = false,
|
|
.stop = false,
|
|
.last = ofs->config.redirect_follow ? false : !poe->numlower,
|
|
.redirect = NULL,
|
|
.metacopy = false,
|
|
};
|
|
|
|
if (dentry->d_name.len > ofs->namelen)
|
|
return ERR_PTR(-ENAMETOOLONG);
|
|
|
|
old_cred = ovl_override_creds(dentry->d_sb);
|
|
upperdir = ovl_dentry_upper(dentry->d_parent);
|
|
if (upperdir) {
|
|
err = ovl_lookup_layer(upperdir, &d, &upperdentry);
|
|
if (err)
|
|
goto out;
|
|
|
|
if (upperdentry && unlikely(ovl_dentry_remote(upperdentry))) {
|
|
dput(upperdentry);
|
|
err = -EREMOTE;
|
|
goto out;
|
|
}
|
|
if (upperdentry && !d.is_dir) {
|
|
unsigned int origin_ctr = 0;
|
|
|
|
/*
|
|
* Lookup copy up origin by decoding origin file handle.
|
|
* We may get a disconnected dentry, which is fine,
|
|
* because we only need to hold the origin inode in
|
|
* cache and use its inode number. We may even get a
|
|
* connected dentry, that is not under any of the lower
|
|
* layers root. That is also fine for using it's inode
|
|
* number - it's the same as if we held a reference
|
|
* to a dentry in lower layer that was moved under us.
|
|
*/
|
|
err = ovl_check_origin(ofs, upperdentry, &origin_path,
|
|
&origin_ctr);
|
|
if (err)
|
|
goto out_put_upper;
|
|
|
|
if (d.metacopy)
|
|
metacopy = true;
|
|
}
|
|
|
|
if (d.redirect) {
|
|
err = -ENOMEM;
|
|
upperredirect = kstrdup(d.redirect, GFP_KERNEL);
|
|
if (!upperredirect)
|
|
goto out_put_upper;
|
|
if (d.redirect[0] == '/')
|
|
poe = roe;
|
|
}
|
|
upperopaque = d.opaque;
|
|
}
|
|
|
|
if (!d.stop && poe->numlower) {
|
|
err = -ENOMEM;
|
|
stack = kcalloc(ofs->numlower, sizeof(struct ovl_path),
|
|
GFP_KERNEL);
|
|
if (!stack)
|
|
goto out_put_upper;
|
|
}
|
|
|
|
for (i = 0; !d.stop && i < poe->numlower; i++) {
|
|
struct ovl_path lower = poe->lowerstack[i];
|
|
|
|
if (!ofs->config.redirect_follow)
|
|
d.last = i == poe->numlower - 1;
|
|
else
|
|
d.last = lower.layer->idx == roe->numlower;
|
|
|
|
err = ovl_lookup_layer(lower.dentry, &d, &this);
|
|
if (err)
|
|
goto out_put;
|
|
|
|
if (!this)
|
|
continue;
|
|
|
|
/*
|
|
* If no origin fh is stored in upper of a merge dir, store fh
|
|
* of lower dir and set upper parent "impure".
|
|
*/
|
|
if (upperdentry && !ctr && !ofs->noxattr && d.is_dir) {
|
|
err = ovl_fix_origin(dentry, this, upperdentry);
|
|
if (err) {
|
|
dput(this);
|
|
goto out_put;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* When "verify_lower" feature is enabled, do not merge with a
|
|
* lower dir that does not match a stored origin xattr. In any
|
|
* case, only verified origin is used for index lookup.
|
|
*
|
|
* For non-dir dentry, if index=on, then ensure origin
|
|
* matches the dentry found using path based lookup,
|
|
* otherwise error out.
|
|
*/
|
|
if (upperdentry && !ctr &&
|
|
((d.is_dir && ovl_verify_lower(dentry->d_sb)) ||
|
|
(!d.is_dir && ofs->config.index && origin_path))) {
|
|
err = ovl_verify_origin(upperdentry, this, false);
|
|
if (err) {
|
|
dput(this);
|
|
if (d.is_dir)
|
|
break;
|
|
goto out_put;
|
|
}
|
|
origin = this;
|
|
}
|
|
|
|
if (d.metacopy)
|
|
metacopy = true;
|
|
/*
|
|
* Do not store intermediate metacopy dentries in chain,
|
|
* except top most lower metacopy dentry
|
|
*/
|
|
if (d.metacopy && ctr) {
|
|
dput(this);
|
|
continue;
|
|
}
|
|
|
|
stack[ctr].dentry = this;
|
|
stack[ctr].layer = lower.layer;
|
|
ctr++;
|
|
|
|
/*
|
|
* Following redirects can have security consequences: it's like
|
|
* a symlink into the lower layer without the permission checks.
|
|
* This is only a problem if the upper layer is untrusted (e.g
|
|
* comes from an USB drive). This can allow a non-readable file
|
|
* or directory to become readable.
|
|
*
|
|
* Only following redirects when redirects are enabled disables
|
|
* this attack vector when not necessary.
|
|
*/
|
|
err = -EPERM;
|
|
if (d.redirect && !ofs->config.redirect_follow) {
|
|
pr_warn_ratelimited("overlayfs: refusing to follow redirect for (%pd2)\n",
|
|
dentry);
|
|
goto out_put;
|
|
}
|
|
|
|
if (d.stop)
|
|
break;
|
|
|
|
if (d.redirect && d.redirect[0] == '/' && poe != roe) {
|
|
poe = roe;
|
|
/* Find the current layer on the root dentry */
|
|
i = lower.layer->idx - 1;
|
|
}
|
|
}
|
|
|
|
if (metacopy) {
|
|
/*
|
|
* Found a metacopy dentry but did not find corresponding
|
|
* data dentry
|
|
*/
|
|
if (d.metacopy) {
|
|
err = -EIO;
|
|
goto out_put;
|
|
}
|
|
|
|
err = -EPERM;
|
|
if (!ofs->config.metacopy) {
|
|
pr_warn_ratelimited("overlay: refusing to follow metacopy origin for (%pd2)\n",
|
|
dentry);
|
|
goto out_put;
|
|
}
|
|
} else if (!d.is_dir && upperdentry && !ctr && origin_path) {
|
|
if (WARN_ON(stack != NULL)) {
|
|
err = -EIO;
|
|
goto out_put;
|
|
}
|
|
stack = origin_path;
|
|
ctr = 1;
|
|
origin_path = NULL;
|
|
}
|
|
|
|
/*
|
|
* Lookup index by lower inode and verify it matches upper inode.
|
|
* We only trust dir index if we verified that lower dir matches
|
|
* origin, otherwise dir index entries may be inconsistent and we
|
|
* ignore them.
|
|
*
|
|
* For non-dir upper metacopy dentry, we already set "origin" if we
|
|
* verified that lower matched upper origin. If upper origin was
|
|
* not present (because lower layer did not support fh encode/decode),
|
|
* or indexing is not enabled, do not set "origin" and skip looking up
|
|
* index. This case should be handled in same way as a non-dir upper
|
|
* without ORIGIN is handled.
|
|
*
|
|
* Always lookup index of non-dir non-metacopy and non-upper.
|
|
*/
|
|
if (ctr && (!upperdentry || (!d.is_dir && !metacopy)))
|
|
origin = stack[0].dentry;
|
|
|
|
if (origin && ovl_indexdir(dentry->d_sb) &&
|
|
(!d.is_dir || ovl_index_all(dentry->d_sb))) {
|
|
index = ovl_lookup_index(ofs, upperdentry, origin, true);
|
|
if (IS_ERR(index)) {
|
|
err = PTR_ERR(index);
|
|
index = NULL;
|
|
goto out_put;
|
|
}
|
|
}
|
|
|
|
oe = ovl_alloc_entry(ctr);
|
|
err = -ENOMEM;
|
|
if (!oe)
|
|
goto out_put;
|
|
|
|
memcpy(oe->lowerstack, stack, sizeof(struct ovl_path) * ctr);
|
|
dentry->d_fsdata = oe;
|
|
|
|
if (upperopaque)
|
|
ovl_dentry_set_opaque(dentry);
|
|
|
|
if (upperdentry)
|
|
ovl_dentry_set_upper_alias(dentry);
|
|
else if (index) {
|
|
upperdentry = dget(index);
|
|
upperredirect = ovl_get_redirect_xattr(upperdentry, 0);
|
|
if (IS_ERR(upperredirect)) {
|
|
err = PTR_ERR(upperredirect);
|
|
upperredirect = NULL;
|
|
goto out_free_oe;
|
|
}
|
|
}
|
|
|
|
if (upperdentry || ctr) {
|
|
struct ovl_inode_params oip = {
|
|
.upperdentry = upperdentry,
|
|
.lowerpath = stack,
|
|
.index = index,
|
|
.numlower = ctr,
|
|
.redirect = upperredirect,
|
|
.lowerdata = (ctr > 1 && !d.is_dir) ?
|
|
stack[ctr - 1].dentry : NULL,
|
|
};
|
|
|
|
inode = ovl_get_inode(dentry->d_sb, &oip);
|
|
err = PTR_ERR(inode);
|
|
if (IS_ERR(inode))
|
|
goto out_free_oe;
|
|
}
|
|
|
|
ovl_revert_creds(old_cred);
|
|
if (origin_path) {
|
|
dput(origin_path->dentry);
|
|
kfree(origin_path);
|
|
}
|
|
dput(index);
|
|
kfree(stack);
|
|
kfree(d.redirect);
|
|
return d_splice_alias(inode, dentry);
|
|
|
|
out_free_oe:
|
|
dentry->d_fsdata = NULL;
|
|
kfree(oe);
|
|
out_put:
|
|
dput(index);
|
|
for (i = 0; i < ctr; i++)
|
|
dput(stack[i].dentry);
|
|
kfree(stack);
|
|
out_put_upper:
|
|
if (origin_path) {
|
|
dput(origin_path->dentry);
|
|
kfree(origin_path);
|
|
}
|
|
dput(upperdentry);
|
|
kfree(upperredirect);
|
|
out:
|
|
kfree(d.redirect);
|
|
ovl_revert_creds(old_cred);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
bool ovl_lower_positive(struct dentry *dentry)
|
|
{
|
|
struct ovl_entry *poe = dentry->d_parent->d_fsdata;
|
|
const struct qstr *name = &dentry->d_name;
|
|
const struct cred *old_cred;
|
|
unsigned int i;
|
|
bool positive = false;
|
|
bool done = false;
|
|
|
|
/*
|
|
* If dentry is negative, then lower is positive iff this is a
|
|
* whiteout.
|
|
*/
|
|
if (!dentry->d_inode)
|
|
return ovl_dentry_is_opaque(dentry);
|
|
|
|
/* Negative upper -> positive lower */
|
|
if (!ovl_dentry_upper(dentry))
|
|
return true;
|
|
|
|
old_cred = ovl_override_creds(dentry->d_sb);
|
|
/* Positive upper -> have to look up lower to see whether it exists */
|
|
for (i = 0; !done && !positive && i < poe->numlower; i++) {
|
|
struct dentry *this;
|
|
struct dentry *lowerdir = poe->lowerstack[i].dentry;
|
|
|
|
this = lookup_positive_unlocked(name->name, lowerdir,
|
|
name->len);
|
|
if (IS_ERR(this)) {
|
|
switch (PTR_ERR(this)) {
|
|
case -ENOENT:
|
|
case -ENAMETOOLONG:
|
|
break;
|
|
|
|
default:
|
|
/*
|
|
* Assume something is there, we just couldn't
|
|
* access it.
|
|
*/
|
|
positive = true;
|
|
break;
|
|
}
|
|
} else {
|
|
positive = !ovl_is_whiteout(this);
|
|
done = true;
|
|
dput(this);
|
|
}
|
|
}
|
|
ovl_revert_creds(old_cred);
|
|
|
|
return positive;
|
|
}
|