| From | Herton Ronaldo Krzesinski <> | Subject | [PATCH 206/270] ext4: Avoid underflow in ext4_trim_fs() | Date | Mon, 26 Nov 2012 14:58:16 -0200 |
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3.5.7u1 -stable review patch. If anyone has any objections, please let me know.
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From: Lukas Czerner <lczerner@redhat.com>
commit 5de35e8d5c02d271c20e18337e01bc20e6ef472e upstream.
Currently if len argument in ext4_trim_fs() is smaller than one block, the 'end' variable underflow. Avoid that by returning EINVAL if len is smaller than file system block.
Also remove useless unlikely().
Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- fs/ext4/mballoc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 70f97a5..af848bb 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4983,8 +4983,9 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) end = start + (range->len >> sb->s_blocksize_bits) - 1; minlen = range->minlen >> sb->s_blocksize_bits; - if (unlikely(minlen > EXT4_CLUSTERS_PER_GROUP(sb)) || - unlikely(start >= max_blks)) + if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) || + start >= max_blks || + range->len < sb->s_blocksize) return -EINVAL; if (end >= max_blks) end = max_blks - 1; -- 1.7.9.5
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