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| author | Josef Bacik <josef@toxicpanda.com> | 2021-03-11 11:23:14 -0500 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-03-17 19:42:12 +0100 |
| commit | 820a49dafc3304de06f296c35c9ff1ebc1666343 (patch) | |
| tree | fa1e3144a305fe06c8f7d6a820e02dea5d3a2199 /fs/btrfs/disk-io.c | |
| parent | 82d62d06db404d03836cdabbca41d38646d97cbb (diff) | |
| download | linux-820a49dafc3304de06f296c35c9ff1ebc1666343.tar.bz2 | |
btrfs: initialize device::fs_info always
Neal reported a panic trying to use -o rescue=all
BUG: kernel NULL pointer dereference, address: 0000000000000030
PGD 0 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 0 PID: 696 Comm: mount Tainted: G W 5.12.0-rc2+ #296
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
RIP: 0010:btrfs_device_init_dev_stats+0x1d/0x200
RSP: 0018:ffffafaec1483bb8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff9a5715bcb298 RCX: 0000000000000070
RDX: ffff9a5703248000 RSI: ffff9a57052ea150 RDI: ffff9a5715bca400
RBP: ffff9a57052ea150 R08: 0000000000000070 R09: ffff9a57052ea150
R10: 000130faf0741c10 R11: 0000000000000000 R12: ffff9a5703700000
R13: 0000000000000000 R14: ffff9a5715bcb278 R15: ffff9a57052ea150
FS: 00007f600d122c40(0000) GS:ffff9a577bc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000030 CR3: 0000000112a46005 CR4: 0000000000370ef0
Call Trace:
? btrfs_init_dev_stats+0x1f/0xf0
? kmem_cache_alloc+0xef/0x1f0
btrfs_init_dev_stats+0x5f/0xf0
open_ctree+0x10cb/0x1720
btrfs_mount_root.cold+0x12/0xea
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
vfs_kern_mount.part.0+0x71/0xb0
btrfs_mount+0x10d/0x380
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
path_mount+0x433/0xa00
__x64_sys_mount+0xe3/0x120
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xae
This happens because when we call btrfs_init_dev_stats we do
device->fs_info->dev_root. However device->fs_info isn't initialized
because we were only calling btrfs_init_devices_late() if we properly
read the device root. However we don't actually need the device root to
init the devices, this function simply assigns the devices their
->fs_info pointer properly, so this needs to be done unconditionally
always so that we can properly dereference device->fs_info in rescue
cases.
Reported-by: Neal Gompa <ngompa13@gmail.com>
CC: stable@vger.kernel.org # 5.11+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
| -rw-r--r-- | fs/btrfs/disk-io.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index c2576c5fe62e..98c46cde7d79 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2387,8 +2387,9 @@ static int btrfs_read_roots(struct btrfs_fs_info *fs_info) } else { set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state); fs_info->dev_root = root; - btrfs_init_devices_late(fs_info); } + /* Initialize fs_info for all devices in any case */ + btrfs_init_devices_late(fs_info); /* If IGNOREDATACSUMS is set don't bother reading the csum root. */ if (!btrfs_test_opt(fs_info, IGNOREDATACSUMS)) { |