3.16.54-rc1 review patch. If anyone has any objections, please let me know.
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From: Colin Ian King colin.king@canonical.com
commit 3993b112dac968612b0b213ed59cb30f50b0015b upstream.
There are checks on fs_info in __btrfs_panic to avoid dereferencing a null fs_info, however, there is a call to btrfs_crit that may also dereference a null fs_info. Fix this by adding a check to see if fs_info is null and only print the s_id if fs_info is non-null.
Detected by CoverityScan CID#401973 ("Dereference after null check")
Fixes: efe120a067c8 ("Btrfs: convert printk to btrfs_ and fix BTRFS prefix") Signed-off-by: Colin Ian King colin.king@canonical.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- fs/btrfs/super.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -185,7 +185,6 @@ static const char * const logtypes[] = {
void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...) { - struct super_block *sb = fs_info->sb; char lvl[4]; struct va_format vaf; va_list args; @@ -207,7 +206,8 @@ void btrfs_printk(const struct btrfs_fs_ vaf.fmt = fmt; vaf.va = &args;
- printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf); + printk("%sBTRFS %s (device %s): %pV\n", lvl, type, + fs_info ? fs_info->sb->s_id : "<unknown>", &vaf);
va_end(args); }