gfs2: add validation checks for size of superblock
[ Upstream commit 0ddc5154b2
]
In gfs2_check_sb(), no validation checks are performed with regards to
the size of the superblock.
syzkaller detected a slab-out-of-bounds bug that was primarily caused
because the block size for a superblock was set to zero.
A valid size for a superblock is a power of 2 between 512 and PAGE_SIZE.
Performing validation checks and ensuring that the size of the superblock
is valid fixes this bug.
Reported-by: syzbot+af90d47a37376844e731@syzkaller.appspotmail.com
Tested-by: syzbot+af90d47a37376844e731@syzkaller.appspotmail.com
Suggested-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
[Minor code reordering.]
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5.4-rM2-2.2.x-imx-squashed
parent
9f7e4bfadf
commit
3c78eb161c
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@ -169,15 +169,19 @@ static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
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return -EINVAL;
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}
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/* If format numbers match exactly, we're done. */
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if (sb->sb_fs_format != GFS2_FORMAT_FS ||
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sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
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fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
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return -EINVAL;
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}
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if (sb->sb_fs_format == GFS2_FORMAT_FS &&
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sb->sb_multihost_format == GFS2_FORMAT_MULTI)
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return 0;
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if (sb->sb_bsize < 512 || sb->sb_bsize > PAGE_SIZE ||
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(sb->sb_bsize & (sb->sb_bsize - 1))) {
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pr_warn("Invalid superblock size\n");
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return -EINVAL;
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}
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fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
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return -EINVAL;
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return 0;
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}
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static void end_bio_io_page(struct bio *bio)
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