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authorZach Brown <zab@redhat.com>2012-07-24 12:10:11 -0700
committerMiklos Szeredi <mszeredi@suse.cz>2012-08-06 18:19:24 +0200
commitfb6ccff667712c46b4501b920ea73a326e49626a (patch)
treef8fa90871e06797a09dd886a2dacf26b199ea667
parentf3840dc0fb57aef120c5ee8241cdc9aaf3cec8d4 (diff)
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fuse: verify all ioctl retry iov elements
Commit 7572777eef78ebdee1ecb7c258c0ef94d35bad16 attempted to verify that the total iovec from the client doesn't overflow iov_length() but it only checked the first element. The iovec could still overflow by starting with a small element. The obvious fix is to check all the elements. The overflow case doesn't look dangerous to the kernel as the copy is limited by the length after the overflow. This fix restores the intention of returning an error instead of successfully copying less than the iovec represented. I found this by code inspection. I built it but don't have a test case. I'm cc:ing stable because the initial commit did as well. Signed-off-by: Zach Brown <zab@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: <stable@vger.kernel.org> [2.6.37+]
-rw-r--r--fs/fuse/file.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 5800101e5ce1..2eed3acfb6a6 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1703,7 +1703,7 @@ static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
size_t n;
u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
- for (n = 0; n < count; n++) {
+ for (n = 0; n < count; n++, iov++) {
if (iov->iov_len > (size_t) max)
return -ENOMEM;
max -= iov->iov_len;