diff options
| author | Pan Bian <bianpan2016@163.com> | 2018-11-23 18:10:15 +0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2019-02-11 17:54:10 +0000 |
| commit | 225ef25362d19fc1fb3870deca0b3110303e99eb (patch) | |
| tree | 1613a0653e2fc79ec934e0dd4d10a4aad3fc39d9 /fs | |
| parent | 3d03e8e5472800f11294d4e1843fead13cc40535 (diff) | |
btrfs: relocation: set trans to be NULL after ending transaction
commit 42a657f57628402c73237547f0134e083e2f6764 upstream.
The function relocate_block_group calls btrfs_end_transaction to release
trans when update_backref_cache returns 1, and then continues the loop
body. If btrfs_block_rsv_refill fails this time, it will jump out the
loop and the freed trans will be accessed. This may result in a
use-after-free bug. The patch assigns NULL to trans after trans is
released so that it will not be accessed.
Fixes: 0647bf564f1 ("Btrfs: improve forever loop when doing balance relocation")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Pan Bian <bianpan2016@163.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/relocation.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index e0029f1a0da8..9cba36820c72 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -3955,6 +3955,7 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc) restart: if (update_backref_cache(trans, &rc->backref_cache)) { btrfs_end_transaction(trans, rc->extent_root); + trans = NULL; continue; } |