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| author | Anand Jain <anand.jain@oracle.com> | 2021-07-04 19:14:39 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-07-22 15:49:49 +0200 |
| commit | 16a200f66ede3f9afa2e51d90ade017aaa18d213 (patch) | |
| tree | 3f6299b73dd61f65065eab964cce6a05f812e230 | |
| parent | 9acc8103ab594f72250788cb45a43427f36d685d (diff) | |
| download | linux-16a200f66ede3f9afa2e51d90ade017aaa18d213.tar.gz linux-16a200f66ede3f9afa2e51d90ade017aaa18d213.tar.bz2 linux-16a200f66ede3f9afa2e51d90ade017aaa18d213.zip | |
btrfs: check for missing device in btrfs_trim_fs
A fstrim on a degraded raid1 can trigger the following null pointer
dereference:
BTRFS info (device loop0): allowing degraded mounts
BTRFS info (device loop0): disk space caching is enabled
BTRFS info (device loop0): has skinny extents
BTRFS warning (device loop0): devid 2 uuid 97ac16f7-e14d-4db1-95bc-3d489b424adb is missing
BTRFS warning (device loop0): devid 2 uuid 97ac16f7-e14d-4db1-95bc-3d489b424adb is missing
BTRFS info (device loop0): enabling ssd optimizations
BUG: kernel NULL pointer dereference, address: 0000000000000620
PGD 0 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 0 PID: 4574 Comm: fstrim Not tainted 5.13.0-rc7+ #31
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
RIP: 0010:btrfs_trim_fs+0x199/0x4a0 [btrfs]
RSP: 0018:ffff959541797d28 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff946f84eca508 RCX: a7a67937adff8608
RDX: ffff946e8122d000 RSI: 0000000000000000 RDI: ffffffffc02fdbf0
RBP: ffff946ea4615000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffff946e8122d960 R12: 0000000000000000
R13: ffff959541797db8 R14: ffff946e8122d000 R15: ffff959541797db8
FS: 00007f55917a5080(0000) GS:ffff946f9bc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000620 CR3: 000000002d2c8001 CR4: 00000000000706f0
Call Trace:
btrfs_ioctl_fitrim+0x167/0x260 [btrfs]
btrfs_ioctl+0x1c00/0x2fe0 [btrfs]
? selinux_file_ioctl+0x140/0x240
? syscall_trace_enter.constprop.0+0x188/0x240
? __x64_sys_ioctl+0x83/0xb0
__x64_sys_ioctl+0x83/0xb0
Reproducer:
$ mkfs.btrfs -fq -d raid1 -m raid1 /dev/loop0 /dev/loop1
$ mount /dev/loop0 /btrfs
$ umount /btrfs
$ btrfs dev scan --forget
$ mount -o degraded /dev/loop0 /btrfs
$ fstrim /btrfs
The reason is we call btrfs_trim_free_extents() for the missing device,
which uses device->bdev (NULL for missing device) to find if the device
supports discard.
Fix is to check if the device is missing before calling
btrfs_trim_free_extents().
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/btrfs/extent-tree.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index d296483d148f..268ce58d4569 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -6019,6 +6019,9 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range) mutex_lock(&fs_info->fs_devices->device_list_mutex); devices = &fs_info->fs_devices->devices; list_for_each_entry(device, devices, dev_list) { + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) + continue; + ret = btrfs_trim_free_extents(device, &group_trimmed); if (ret) { dev_failed++; |