btrfs/049 fails with null pointer dereference
kernel: BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
::
kernel: RIP: 0010:write_pinned_extent_entries+0x27/0x100 [btrfs]
::
kernel: Call Trace:
kernel: __btrfs_write_out_cache+0x273/0x450 [btrfs]
kernel: btrfs_write_out_ino_cache+0x84/0xd0 [btrfs]
kernel: btrfs_save_ino_cache+0x414/0x500 [btrfs]
kernel: commit_fs_roots+0xc6/0x190 [btrfs]
kernel: btrfs_commit_transaction+0x4de/0xac0 [btrfs]
kernel: btrfs_sync_file+0x35b/0x3d0 [btrfs]
kernel: do_fsync+0x38/0x60
kernel: __x64_sys_fsync+0x10/0x20
%block_group::fs_info should be accessed only when block_group is not null.
(Fixes: de965ddc6f29 btrfs: get fs_info from block group in
write_pinned_extent_entries)
Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
---
fs/btrfs/free-space-cache.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index ea7fecf63fbb..a065041e7c80 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1044,7 +1044,7 @@ static noinline_for_stack int write_pinned_extent_entries(
struct btrfs_io_ctl *io_ctl,
int *entries)
{
- struct btrfs_fs_info *fs_info = block_group->fs_info;
+ struct btrfs_fs_info *fs_info;
u64 start, extent_start, extent_end, len;
struct extent_io_tree *unpin = NULL;
int ret;
@@ -1052,6 +1052,7 @@ static noinline_for_stack int write_pinned_extent_entries(
if (!block_group)
return 0;
+ fs_info = block_group->fs_info;
/*
* We want to add any pinned extents to our free space cache
* so we don't leak the space
--
2.20.1 (Apple Git-117)
