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| author | Haogang Chen <haogangchen@gmail.com> | 2011-12-20 02:11:56 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-12-20 19:25:04 +0100 |
| commit | 481fe17e973fb97aa3edf17c69557afe88d8334f (patch) | |
| tree | 3ab58a5f35345d7e61fc4428b18529705ceab1e5 /fs/nilfs2/ioctl.c | |
| parent | nilfs2: unbreak compat ioctl (diff) | |
| download | linux-481fe17e973fb97aa3edf17c69557afe88d8334f.tar.xz linux-481fe17e973fb97aa3edf17c69557afe88d8334f.zip | |
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/ioctl.c')
| -rw-r--r-- | fs/nilfs2/ioctl.c | 3 |
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) { |