[5.10,21/29] ovl: fix leaked dentry

Message ID	20210505112326.902604523@linuxfoundation.org
State	New
Headers	show Return-Path: <stable-owner@kernel.org> 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>, =?utf-8?q?Micka=C3=ABl_Sa?= =?utf-8?b?bGHDvG4=?= <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 Message-Id: <20210505112326.902604523@linuxfoundation.org> In-Reply-To: <20210505112326.195493232@linuxfoundation.org> References: <20210505112326.195493232@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	None \| expand [5.10,02/29] netfilter: conntrack: Make global sysctls readonly in non-init netns [5.10,03/29] net: usb: ax88179_178a: initialize local variables before use [5.10,04/29] igb: Enable RSS for Intel I211 Ethernet Controller [5.10,05/29] bpf: Fix masking negation logic upon negative dst register [5.10,06/29] bpf: Fix leakage of uninitialized bpf stack under speculation [5.10,07/29] net: qrtr: Avoid potential use after free in MHI send [5.10,08/29] perf data: Fix error return code in perf_data__create_dir() [5.10,09/29] capabilities: require CAP_SETFCAP to map uid 0 [5.10,10/29] perf ftrace: Fix access to pid in array when setting a pid filter [5.10,11/29] tools/cgroup/slabinfo.py: updated to work on current kernel [5.10,12/29] driver core: add a min_align_mask field to struct device_dma_parameters [5.10,13/29] swiotlb: add a IO_TLB_SIZE define [5.10,14/29] swiotlb: factor out an io_tlb_offset helper [5.10,15/29] swiotlb: factor out a nr_slots helper [5.10,16/29] swiotlb: clean up swiotlb_tbl_unmap_single [5.10,17/29] swiotlb: refactor swiotlb_tbl_map_single [5.10,18/29] swiotlb: dont modify orig_addr in swiotlb_tbl_sync_single [5.10,19/29] swiotlb: respect min_align_mask [5.10,20/29] nvme-pci: set min_align_mask [5.10,21/29] ovl: fix leaked dentry [5.10,22/29] ovl: allow upperdir inside lowerdir [5.10,23/29] ALSA: usb-audio: Add MIDI quirk for Vox ToneLab EX [5.10,24/29] USB: Add LPM quirk for Lenovo ThinkPad USB-C Dock Gen2 Ethernet [5.10,25/29] USB: Add reset-resume quirk for WD19s Realtek Hub [5.10,26/29] ASoC: ak4458: Add MODULE_DEVICE_TABLE [5.10,27/29] ASoC: ak5558: Add MODULE_DEVICE_TABLE [5.10,28/29] platform/x86: thinkpad_acpi: Correct thermal sensor allocation [5.10,29/29] perf/core: Fix unconditional security_locked_down() call

Message ID

20210505112326.902604523@linuxfoundation.org

State

New

Headers

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>, =?utf-8?q?Micka=C3=ABl_Sa?=
	=?utf-8?b?bGHDvG4=?= <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
Message-Id: <20210505112326.902604523@linuxfoundation.org>
In-Reply-To: <20210505112326.195493232@linuxfoundation.org>
References: <20210505112326.195493232@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

Series

None | expand

Commit Message

Greg KH May 5, 2021, 12:05 p.m. UTC

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;

[5.10,21/29] ovl: fix leaked dentry

Commit Message

Patch