diff options
| author | Pan Bian <bianpan2016@163.com> | 2018-11-23 18:10:15 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-05 19:32:07 +0100 |
| commit | 590657656bdcf682fa3667dd7c768b3541558619 (patch) | |
| tree | d9f4dae0aaedc2f40a726f4c1a132158c0be46fd | |
| parent | 172a94eb2df2006a795af44cb1ffa330ad85572a (diff) | |
| download | linux-stable-590657656bdcf682fa3667dd7c768b3541558619.tar.gz linux-stable-590657656bdcf682fa3667dd7c768b3541558619.tar.bz2 linux-stable-590657656bdcf682fa3667dd7c768b3541558619.zip | |
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")
CC: stable@vger.kernel.org # 4.4+
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 60bf8dfe7df4..0526b6c473c7 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -3963,6 +3963,7 @@ 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); + trans = NULL; continue; } |