ext4: remove a BUG_ON in ext4_mb_release_group_pa()

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commit 463808f237 upstream.

If a malicious fuzzer overwrites the ext4 superblock while it is
mounted such that the s_first_data_block is set to a very large
number, the calculation of the block group can underflow, and trigger
a BUG_ON check.  Change this to be an ext4_warning so that we don't
crash the kernel.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230430154311.579720-3-tytso@mit.edu
Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Theodore Ts'o 2023-04-29 16:14:46 -04:00 • committed by Greg Kroah-Hartman

parent 19fb73b8ea

commit d87a4e4094

1 changed files with 5 additions and 1 deletions

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fs/ext4/mballoc.c

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