diff options
author | Pan Bian <bianpan2016@163.com> | 2018-11-23 13:10:15 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-05 21:41:23 +0300 |
commit | e380f318e63d851607cfc8b288281668aad11d53 (patch) | |
tree | 0b741aba9fe73e2b10be34a389379997fc82e971 /fs | |
parent | 52fa8eaac8149594d57bd4fe0cfeaa329037d400 (diff) | |
download | linux-e380f318e63d851607cfc8b288281668aad11d53.tar.xz |
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>
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 eeae2c3ab17e..5feb8b03ffe8 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -4048,6 +4048,7 @@ 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; } |