linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, "Amir Goldstein" <amir73il@gmail.com>,
	syzbot <syzkaller@googlegroups.com>,
	"Mickaël Salaün" <mic@linux.microsoft.com>,
	"Vivek Goyal" <vgoyal@redhat.com>,
	"Miklos Szeredi" <mszeredi@redhat.com>
Subject: [PATCH 5.10 21/29] ovl: fix leaked dentry
Date: Wed,  5 May 2021 14:05:24 +0200	[thread overview]
Message-ID: <20210505112326.902604523@linuxfoundation.org> (raw)
In-Reply-To: <20210505112326.195493232@linuxfoundation.org>

From: Mickaël Salaün <mic@linux.microsoft.com>

commit eaab1d45cdb4bb0c846bd23c3d666d5b90af7b41 upstream.

Since commit 6815f479ca90 ("ovl: use only uppermetacopy state in
ovl_lookup()"), overlayfs doesn't put temporary dentry when there is a
metacopy error, which leads to dentry leaks when shutting down the related
superblock:

  overlayfs: refusing to follow metacopy origin for (/file0)
  ...
  BUG: Dentry (____ptrval____){i=3f33,n=file3}  still in use (1) [unmount of overlay overlay]
  ...
  WARNING: CPU: 1 PID: 432 at umount_check.cold+0x107/0x14d
  CPU: 1 PID: 432 Comm: unmount-overlay Not tainted 5.12.0-rc5 #1
  ...
  RIP: 0010:umount_check.cold+0x107/0x14d
  ...
  Call Trace:
   d_walk+0x28c/0x950
   ? dentry_lru_isolate+0x2b0/0x2b0
   ? __kasan_slab_free+0x12/0x20
   do_one_tree+0x33/0x60
   shrink_dcache_for_umount+0x78/0x1d0
   generic_shutdown_super+0x70/0x440
   kill_anon_super+0x3e/0x70
   deactivate_locked_super+0xc4/0x160
   deactivate_super+0xfa/0x140
   cleanup_mnt+0x22e/0x370
   __cleanup_mnt+0x1a/0x30
   task_work_run+0x139/0x210
   do_exit+0xb0c/0x2820
   ? __kasan_check_read+0x1d/0x30
   ? find_held_lock+0x35/0x160
   ? lock_release+0x1b6/0x660
   ? mm_update_next_owner+0xa20/0xa20
   ? reacquire_held_locks+0x3f0/0x3f0
   ? __sanitizer_cov_trace_const_cmp4+0x22/0x30
   do_group_exit+0x135/0x380
   __do_sys_exit_group.isra.0+0x20/0x20
   __x64_sys_exit_group+0x3c/0x50
   do_syscall_64+0x45/0x70
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  ...
  VFS: Busy inodes after unmount of overlay. Self-destruct in 5 seconds.  Have a nice day...

This fix has been tested with a syzkaller reproducer.

Cc: Amir Goldstein <amir73il@gmail.com>
Cc: <stable@vger.kernel.org> # v5.8+
Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 6815f479ca90 ("ovl: use only uppermetacopy state in ovl_lookup()")
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Link: https://lore.kernel.org/r/20210329164907.2133175-1-mic@digikod.net
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/overlayfs/namei.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -913,6 +913,7 @@ struct dentry *ovl_lookup(struct inode *
 			continue;
 
 		if ((uppermetacopy || d.metacopy) && !ofs->config.metacopy) {
+			dput(this);
 			err = -EPERM;
 			pr_warn_ratelimited("refusing to follow metacopy origin for (%pd2)\n", dentry);
 			goto out_put;



  parent reply	other threads:[~2021-05-05 12:07 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-05 12:05 [PATCH 5.10 00/29] 5.10.35-rc1 review Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 01/29] mips: Do not include hi and lo in clobber list for R6 Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 02/29] netfilter: conntrack: Make global sysctls readonly in non-init netns Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 03/29] net: usb: ax88179_178a: initialize local variables before use Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 04/29] igb: Enable RSS for Intel I211 Ethernet Controller Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 05/29] bpf: Fix masking negation logic upon negative dst register Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 06/29] bpf: Fix leakage of uninitialized bpf stack under speculation Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 07/29] net: qrtr: Avoid potential use after free in MHI send Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 08/29] perf data: Fix error return code in perf_data__create_dir() Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 09/29] capabilities: require CAP_SETFCAP to map uid 0 Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 10/29] perf ftrace: Fix access to pid in array when setting a pid filter Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 11/29] tools/cgroup/slabinfo.py: updated to work on current kernel Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 12/29] driver core: add a min_align_mask field to struct device_dma_parameters Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 13/29] swiotlb: add a IO_TLB_SIZE define Greg Kroah-Hartman
2021-05-05 20:45   ` Yet another way to mark upstream commits was " Pavel Machek
2021-05-05 12:05 ` [PATCH 5.10 14/29] swiotlb: factor out an io_tlb_offset helper Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 15/29] swiotlb: factor out a nr_slots helper Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 16/29] swiotlb: clean up swiotlb_tbl_unmap_single Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 17/29] swiotlb: refactor swiotlb_tbl_map_single Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 18/29] swiotlb: dont modify orig_addr in swiotlb_tbl_sync_single Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 19/29] swiotlb: respect min_align_mask Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 20/29] nvme-pci: set min_align_mask Greg Kroah-Hartman
2021-05-05 12:05 ` Greg Kroah-Hartman [this message]
2021-05-05 12:05 ` [PATCH 5.10 22/29] ovl: allow upperdir inside lowerdir Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 23/29] ALSA: usb-audio: Add MIDI quirk for Vox ToneLab EX Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 24/29] USB: Add LPM quirk for Lenovo ThinkPad USB-C Dock Gen2 Ethernet Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 25/29] USB: Add reset-resume quirk for WD19s Realtek Hub Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 26/29] ASoC: ak4458: Add MODULE_DEVICE_TABLE Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 27/29] ASoC: ak5558: " Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 28/29] platform/x86: thinkpad_acpi: Correct thermal sensor allocation Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.10 29/29] perf/core: Fix unconditional security_locked_down() call Greg Kroah-Hartman
2021-05-05 15:04 ` [PATCH 5.10 00/29] 5.10.35-rc1 review Patrick Mccormick
2021-05-05 19:30 ` Florian Fainelli
2021-05-05 20:19 ` Fox Chen
2021-05-05 21:04 ` Shuah Khan
2021-05-06  1:50 ` Guenter Roeck
2021-05-06  2:52 ` Samuel Zou
2021-05-06  7:46 ` Naresh Kamboju
2021-05-06  8:57 ` Pavel Machek
2021-05-06 10:07 ` Sudip Mukherjee

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210505112326.902604523@linuxfoundation.org \
    --to=gregkh@linuxfoundation.org \
    --cc=amir73il@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mic@linux.microsoft.com \
    --cc=mszeredi@redhat.com \
    --cc=stable@vger.kernel.org \
    --cc=syzkaller@googlegroups.com \
    --cc=vgoyal@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).