From patchwork Thu Nov 22 04:47:08 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3.5.yuz, extended, stable] Patch "ext4: Avoid underflow in ext4_trim_fs()" has been added to staging queue Date: Wed, 21 Nov 2012 18:47:08 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 200961 Message-Id: <1353559628-845-1-git-send-email-herton.krzesinski@canonical.com> To: Lukas Czerner Cc: kernel-team@lists.ubuntu.com, Theodore Ts'o This is a note to let you know that I have just added a patch titled ext4: Avoid underflow in ext4_trim_fs() to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.yuz tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ >From 72b839359359aa6e2e349a6481f3268aad009e76 Mon Sep 17 00:00:00 2001 From: Lukas Czerner Date: Mon, 22 Oct 2012 18:01:19 -0400 Subject: [PATCH] ext4: Avoid underflow in ext4_trim_fs() 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 Signed-off-by: "Theodore Ts'o" Signed-off-by: Herton Ronaldo Krzesinski --- fs/ext4/mballoc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) -- 1.7.9.5 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;