]> git.proxmox.com Git - mirror_ubuntu-disco-kernel.git/commit
nilfs2: potential integer overflow in nilfs_ioctl_clean_segments()
authorHaogang Chen <haogangchen@gmail.com>
Tue, 20 Dec 2011 01:11:56 +0000 (17:11 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 20 Dec 2011 18:25:04 +0000 (10:25 -0800)
commit481fe17e973fb97aa3edf17c69557afe88d8334f
tree3ab58a5f35345d7e61fc4428b18529705ceab1e5
parent695c60f21c69e525a89279a5f35bae4ff237afbc
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>
fs/nilfs2/ioctl.c