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authorHaogang Chen <haogangchen@gmail.com>2011-12-19 17:11:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-12-20 10:25:04 -0800
commit481fe17e973fb97aa3edf17c69557afe88d8334f (patch)
tree3ab58a5f35345d7e61fc4428b18529705ceab1e5 /fs/nilfs2
parent695c60f21c69e525a89279a5f35bae4ff237afbc (diff)
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nilfs2: potential integer overflow in nilfs_ioctl_clean_segments()
There is a potential integer overflow in nilfs_ioctl_clean_segments(). When a large argv[n].v_nmembs is passed from the userspace, the subsequent call to vmalloc() will allocate a buffer smaller than expected, which leads to out-of-bound access in nilfs_ioctl_move_blocks() and lfs_clean_segments(). The following check does not prevent the overflow because nsegs is also controlled by the userspace and could be very large. if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment) goto out_free; This patch clamps argv[n].v_nmembs to UINT_MAX / argv[n].v_size, and returns -EINVAL when overflow. Signed-off-by: Haogang Chen <haogangchen@gmail.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/nilfs2')
-rw-r--r--fs/nilfs2/ioctl.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 3e654273cfc2..ac258beeda3c 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -625,6 +625,9 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment)
goto out_free;
+ if (argv[n].v_nmembs >= UINT_MAX / argv[n].v_size)
+ goto out_free;
+
len = argv[n].v_size * argv[n].v_nmembs;
base = (void __user *)(unsigned long)argv[n].v_base;
if (len == 0) {