From bcb7e449ec6350121ac7ca138c0b050ba7caca47 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 16 Mar 2015 17:38:02 -0400 Subject: [PATCH] Btrfs: just free dummy extent buffers If we fail during our sanity tests we could get NULL deref's because we unload the module before the dummy extent buffers are free'd via RCU. So check for this case and just free the things directly. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/extent_io.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 29850d4a3827..d13ceadcbf18 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4968,6 +4968,12 @@ static int release_extent_buffer(struct extent_buffer *eb) /* Should be safe to release our pages at this point */ btrfs_release_extent_buffer_page(eb); +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS + if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) { + __free_extent_buffer(eb); + return 1; + } +#endif call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu); return 1; }