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authorZach Brown <zab@redhat.com>2012-07-24 12:10:11 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-08-26 15:12:11 -0700
commitbd697182ee0264c6a6c9ac108d5d765e24b82724 (patch)
treee1e23e0a6546d7d153f3710d8511284999cd574e
parent44d3398477f343c8d63f7219ef0594fa06644e0a (diff)
fuse: verify all ioctl retry iov elements
commit fb6ccff667712c46b4501b920ea73a326e49626a upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 82a66466a24c..79fca8dfa3ea 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1710,7 +1710,7 @@ 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;