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authorMiklos Szeredi <mszeredi@suse.cz>2010-11-30 18:39:27 +0300
committerMiklos Szeredi <mszeredi@suse.cz>2010-11-30 18:39:27 +0300
commit7572777eef78ebdee1ecb7c258c0ef94d35bad16 (patch)
tree04bb06d75688912ac14855146dc013703529403d /fs/fuse
parentd9d318d39dd5cb686660504a3565aac453709ccc (diff)
downloadlinux-7572777eef78ebdee1ecb7c258c0ef94d35bad16.tar.xz
fuse: verify ioctl retries
Verify that the total length of the iovec returned in FUSE_IOCTL_RETRY doesn't overflow iov_length(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: Tejun Heo <tj@kernel.org> CC: <stable@kernel.org> [2.6.31+]
Diffstat (limited to 'fs/fuse')
-rw-r--r--fs/fuse/file.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 0e2e25b114a6..8b984a2cebbd 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1666,6 +1666,20 @@ static int fuse_copy_ioctl_iovec(struct iovec *dst, void *src,
return 0;
}
+/* Make sure iov_length() won't overflow */
+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++) {
+ if (iov->iov_len > (size_t) max)
+ return -ENOMEM;
+ max -= iov->iov_len;
+ }
+ return 0;
+}
+
/*
* For ioctls, there is no generic way to determine how much memory
* needs to be read and/or written. Furthermore, ioctls are allowed
@@ -1858,6 +1872,14 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
in_iov = page_address(iov_page);
out_iov = in_iov + in_iovs;
+ err = fuse_verify_ioctl_iov(in_iov, in_iovs);
+ if (err)
+ goto out;
+
+ err = fuse_verify_ioctl_iov(out_iov, out_iovs);
+ if (err)
+ goto out;
+
goto retry;
}