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| author | Johannes Thumshirn <johannes.thumshirn@wdc.com> | 2020-01-08 15:07:32 +0300 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2020-01-08 19:56:17 +0300 |
| commit | 26ef8493e1ab771cb01d27defca2fa1315dc3980 (patch) | |
| tree | f333b668c6c743067df3b19e20571f7ddd57c69d | |
| parent | 423a716cd7be16fb08690760691befe3be97d3fc (diff) | |
| download | linux-26ef8493e1ab771cb01d27defca2fa1315dc3980.tar.xz | |
btrfs: fix memory leak in qgroup accounting
When running xfstests on the current btrfs I get the following splat from
kmemleak:
unreferenced object 0xffff88821b2404e0 (size 32):
comm "kworker/u4:7", pid 26663, jiffies 4295283698 (age 8.776s)
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 10 ff fd 26 82 88 ff ff ...........&....
10 ff fd 26 82 88 ff ff 20 ff fd 26 82 88 ff ff ...&.... ..&....
backtrace:
[<00000000f94fd43f>] ulist_alloc+0x25/0x60 [btrfs]
[<00000000fd023d99>] btrfs_find_all_roots_safe+0x41/0x100 [btrfs]
[<000000008f17bd32>] btrfs_find_all_roots+0x52/0x70 [btrfs]
[<00000000b7660afb>] btrfs_qgroup_rescan_worker+0x343/0x680 [btrfs]
[<0000000058e66778>] btrfs_work_helper+0xac/0x1e0 [btrfs]
[<00000000f0188930>] process_one_work+0x1cf/0x350
[<00000000af5f2f8e>] worker_thread+0x28/0x3c0
[<00000000b55a1add>] kthread+0x109/0x120
[<00000000f88cbd17>] ret_from_fork+0x35/0x40
This corresponds to:
(gdb) l *(btrfs_find_all_roots_safe+0x41)
0x8d7e1 is in btrfs_find_all_roots_safe (fs/btrfs/backref.c:1413).
1408
1409 tmp = ulist_alloc(GFP_NOFS);
1410 if (!tmp)
1411 return -ENOMEM;
1412 *roots = ulist_alloc(GFP_NOFS);
1413 if (!*roots) {
1414 ulist_free(tmp);
1415 return -ENOMEM;
1416 }
1417
Following the lifetime of the allocated 'roots' ulist, it gets freed
again in btrfs_qgroup_account_extent().
But this does not happen if the function is called with the
'BTRFS_FS_QUOTA_ENABLED' flag cleared, then btrfs_qgroup_account_extent()
does a short leave and directly returns.
Instead of directly returning we should jump to the 'out_free' in order to
free all resources as expected.
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/btrfs/qgroup.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index d4282e12f2a6..39fc8c3d3a75 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -2423,8 +2423,12 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, u64 nr_old_roots = 0; int ret = 0; + /* + * If quotas get disabled meanwhile, the resouces need to be freed and + * we can't just exit here. + */ if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) - return 0; + goto out_free; if (new_roots) { if (!maybe_fs_roots(new_roots)) |