lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <0E92A0AB-4F16-4F1A-94B7-702CC6504FDE@amazon.com> Date: Wed, 20 Jul 2022 04:27:48 +0000 From: "Kiselev, Oleg" <okiselev@...zon.com> To: "linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org> CC: Theodore Ts'o <tytso@....edu>, Jan Kara <jack@...e.cz> Subject: [PATCH -V2 2/2] ext4: avoid resizing to a partial cluster size This patch avoids an attempt to resize the filesystem to an unaligned cluster boundary. An online resize to a size that is not integral to cluster size results in the last iteration attempting to grow the fs by a negative amount, which trips a BUG_ON and leaves the fs with a corrupted in-memory superblock. Signed-off-by: Oleg Kiselev <okiselev@...zon.com> --- v2: - Moved the code higher up in the call stack, changed the implementation to trim the request size --- fs/ext4/resize.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index a69113b4ce4e..b69fda478e9d 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -2007,6 +2007,16 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t ) } brelse(bh); + /* + * For bigalloc, trim the requested size to the nearest cluster + * boundary to avoid creating an unusable filesystem. We do this + * silently, instead of returning an error, to avoid breaking + * callers that blindly resize the filesystem to the full size of + * the underlying block device. + */ + if (ext4_has_feature_bigalloc(sb)) + n_blocks_count &= ~((1 << EXT4_CLUSTER_BITS(sb)) - 1); + retry: o_blocks_count = ext4_blocks_count(es); -- 2.34.3
Powered by blists - more mailing lists