Commit f451fd97 authored by Fabio M. De Francesco's avatar Fabio M. De Francesco Committed by Theodore Ts'o
Browse files

ext4: drop the call to ext4_error() from ext4_get_group_info() 



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: default avatar <syzbot+4acc7d910e617b360859@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/all/00000000000070575805fdc6cdb2@google.com/


Fixes: 5354b2af ("ext4: allow ext4_get_group_info() to fail")
Suggested-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarFabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20230614100446.14337-1-fmdefrancesco@gmail.com
parent 19482792

fs/ext4/balloc.c

+9 −11
Original line number Diff line number Diff line
@@ -327,10 +327,8 @@ struct ext4_group_info *ext4_get_group_info(struct super_block *sb, 
	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);

	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);