From: Fabio M. De Francesco fmdefrancesco@gmail.com
[ Upstream commit f451fd97dd2b78f286379203a47d9d295c467255 ]
A recent patch added a call to ext4_error() which is problematic since some callers of the ext4_get_group_info() function may be holding a spinlock, whereas ext4_error() must never be called in atomic context.
This triggered a report from Syzbot: "BUG: sleeping function called from invalid context in ext4_update_super" (see the link below).
Therefore, drop the call to ext4_error() from ext4_get_group_info(). In the meantime use eight characters tabs instead of nine characters ones.
Reported-by: syzbot+4acc7d910e617b360859@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/00000000000070575805fdc6cdb2@google.com/ Fixes: 5354b2af3406 ("ext4: allow ext4_get_group_info() to fail") Suggested-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Fabio M. De Francesco fmdefrancesco@gmail.com Link: https://lore.kernel.org/r/20230614100446.14337-1-fmdefrancesco@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext4/balloc.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index a43167042b6b1..4efe71efe1277 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -322,17 +322,15 @@ static ext4_fsblk_t ext4_valid_block_bitmap_padding(struct super_block *sb, struct ext4_group_info *ext4_get_group_info(struct super_block *sb, ext4_group_t group) { - struct ext4_group_info **grp_info; - long indexv, indexh; - - if (unlikely(group >= EXT4_SB(sb)->s_groups_count)) { - ext4_error(sb, "invalid group %u", group); - return NULL; - } - indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb)); - indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1); - grp_info = sbi_array_rcu_deref(EXT4_SB(sb), s_group_info, indexv); - return grp_info[indexh]; + struct ext4_group_info **grp_info; + long indexv, indexh; + + if (unlikely(group >= EXT4_SB(sb)->s_groups_count)) + return NULL; + indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb)); + indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1); + grp_info = sbi_array_rcu_deref(EXT4_SB(sb), s_group_info, indexv); + return grp_info[indexh]; }
/*