aio: fix the compat vectored operations

The aio compat code was not converting the struct iovecs from 32bit to
64bit pointers, causing either EINVAL to be returned from io_getevents, or
EFAULT as the result of the I/O.  This patch passes a compat flag to
io_submit to signal that pointer conversion is necessary for a given iocb
array.

A variant of this was tested by Michael Tokarev.  I have also updated the
libaio test harness to exercise this code path with good success.
Further, I grabbed a copy of ltp and ran the
testcases/kernel/syscall/readv and writev tests there (compiled with -m32
on my 64bit system).  All seems happy, but extra eyes on this would be
welcome.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix CONFIG_COMPAT=n build]
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: <stable@kernel.org>		[2.6.35.1]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/aio.c b/fs/aio.c
index 1cf12b3dd83a0654d7c0629786d8ab7fd4388a23..48fdeebdb544df9e008affb6814789035d4e94ce 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -36,6 +36,7 @@
 #include <linux/blkdev.h>
 #include <linux/mempool.h>
 #include <linux/hash.h>
+#include <linux/compat.h>
 
 #include <asm/kmap_types.h>
 #include <asm/uaccess.h>
@@ -1384,13 +1385,22 @@ static ssize_t aio_fsync(struct kiocb *iocb)
        return ret;
 }
 
-static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb)
+static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb, bool compat)
 {
        ssize_t ret;
 
-       ret = rw_copy_check_uvector(type, (struct iovec __user *)kiocb->ki_buf,
-                                   kiocb->ki_nbytes, 1,
-                                   &kiocb->ki_inline_vec, &kiocb->ki_iovec);
+#ifdef CONFIG_COMPAT
+       if (compat)
+               ret = compat_rw_copy_check_uvector(type,
+                               (struct compat_iovec __user *)kiocb->ki_buf,
+                               kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
+                               &kiocb->ki_iovec);
+       else
+#endif
+               ret = rw_copy_check_uvector(type,
+                               (struct iovec __user *)kiocb->ki_buf,
+                               kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
+                               &kiocb->ki_iovec);
        if (ret < 0)
                goto out;
 
@@ -1420,7 +1430,7 @@ static ssize_t aio_setup_single_vector(struct kiocb *kiocb)
  *     Performs the initial checks and aio retry method
  *     setup for the kiocb at the time of io submission.
  */
-static ssize_t aio_setup_iocb(struct kiocb *kiocb)
+static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
 {
        struct file *file = kiocb->ki_filp;
        ssize_t ret = 0;
@@ -1469,7 +1479,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb)
                ret = security_file_permission(file, MAY_READ);
                if (unlikely(ret))
                        break;
-               ret = aio_setup_vectored_rw(READ, kiocb);
+               ret = aio_setup_vectored_rw(READ, kiocb, compat);
                if (ret)
                        break;
                ret = -EINVAL;
@@ -1483,7 +1493,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb)
                ret = security_file_permission(file, MAY_WRITE);
                if (unlikely(ret))
                        break;
-               ret = aio_setup_vectored_rw(WRITE, kiocb);
+               ret = aio_setup_vectored_rw(WRITE, kiocb, compat);
                if (ret)
                        break;
                ret = -EINVAL;
@@ -1548,7 +1558,8 @@ static void aio_batch_free(struct hlist_head *batch_hash)
 }
 
 static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
-                        struct iocb *iocb, struct hlist_head *batch_hash)
+                        struct iocb *iocb, struct hlist_head *batch_hash,
+                        bool compat)
 {
        struct kiocb *req;
        struct file *file;
@@ -1609,7 +1620,7 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
        req->ki_left = req->ki_nbytes = iocb->aio_nbytes;
        req->ki_opcode = iocb->aio_lio_opcode;
 
-       ret = aio_setup_iocb(req);
+       ret = aio_setup_iocb(req, compat);
 
        if (ret)
                goto out_put_req;
@@ -1637,20 +1648,8 @@ out_put_req:
        return ret;
 }
 
-/* sys_io_submit:
- *     Queue the nr iocbs pointed to by iocbpp for processing.  Returns
- *     the number of iocbs queued.  May return -EINVAL if the aio_context
- *     specified by ctx_id is invalid, if nr is < 0, if the iocb at
- *     *iocbpp[0] is not properly initialized, if the operation specified
- *     is invalid for the file descriptor in the iocb.  May fail with
- *     -EFAULT if any of the data structures point to invalid data.  May
- *     fail with -EBADF if the file descriptor specified in the first
- *     iocb is invalid.  May fail with -EAGAIN if insufficient resources
- *     are available to queue any iocbs.  Will return 0 if nr is 0.  Will
- *     fail with -ENOSYS if not implemented.
- */
-SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
-               struct iocb __user * __user *, iocbpp)
+long do_io_submit(aio_context_t ctx_id, long nr,
+                 struct iocb __user *__user *iocbpp, bool compat)
 {
        struct kioctx *ctx;
        long ret = 0;
@@ -1687,7 +1686,7 @@ SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
                        break;
                }
 
-               ret = io_submit_one(ctx, user_iocb, &tmp, batch_hash);
+               ret = io_submit_one(ctx, user_iocb, &tmp, batch_hash, compat);
                if (ret)
                        break;
        }
@@ -1697,6 +1696,24 @@ SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
        return i ? i : ret;
 }
 
+/* sys_io_submit:
+ *     Queue the nr iocbs pointed to by iocbpp for processing.  Returns
+ *     the number of iocbs queued.  May return -EINVAL if the aio_context
+ *     specified by ctx_id is invalid, if nr is < 0, if the iocb at
+ *     *iocbpp[0] is not properly initialized, if the operation specified
+ *     is invalid for the file descriptor in the iocb.  May fail with
+ *     -EFAULT if any of the data structures point to invalid data.  May
+ *     fail with -EBADF if the file descriptor specified in the first
+ *     iocb is invalid.  May fail with -EAGAIN if insufficient resources
+ *     are available to queue any iocbs.  Will return 0 if nr is 0.  Will
+ *     fail with -ENOSYS if not implemented.
+ */
+SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
+               struct iocb __user * __user *, iocbpp)
+{
+       return do_io_submit(ctx_id, nr, iocbpp, 0);
+}
+
 /* lookup_kiocb
  *     Finds a given iocb for cancellation.
  */

diff --git a/fs/compat.c b/fs/compat.c
index 7b4aabb3bb36b3966d0497bd5656d87b5925b394..f0b391c50552dc986f93afe1e4c56ce3b777a600 100644 (file)
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -673,7 +673,7 @@ compat_sys_io_submit(aio_context_t ctx_id, int nr, u32 __user *iocb)
        iocb64 = compat_alloc_user_space(nr * sizeof(*iocb64));
        ret = copy_iocb(nr, iocb, iocb64);
        if (!ret)
-               ret = sys_io_submit(ctx_id, nr, iocb64);
+               ret = do_io_submit(ctx_id, nr, iocb64, 1);
        return ret;
 }
 

diff --git a/include/linux/aio.h b/include/linux/aio.h
index 811dbb369379ff463110289bba1d44b9bb14a2a2..7a8db41552813ff15e6739943ad401cfe5f56b3c 100644 (file)
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -212,6 +212,8 @@ extern void kick_iocb(struct kiocb *iocb);
 extern int aio_complete(struct kiocb *iocb, long res, long res2);
 struct mm_struct;
 extern void exit_aio(struct mm_struct *mm);
+extern long do_io_submit(aio_context_t ctx_id, long nr,
+                        struct iocb __user *__user *iocbpp, bool compat);
 #else
 static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; }
 static inline int aio_put_req(struct kiocb *iocb) { return 0; }
@@ -219,6 +221,9 @@ static inline void kick_iocb(struct kiocb *iocb) { }
 static inline int aio_complete(struct kiocb *iocb, long res, long res2) { return 0; }
 struct mm_struct;
 static inline void exit_aio(struct mm_struct *mm) { }
+static inline long do_io_submit(aio_context_t ctx_id, long nr,
+                               struct iocb __user * __user *iocbpp,
+                               bool compat) { return 0; }
 #endif /* CONFIG_AIO */
 
 static inline struct kiocb *list_kiocb(struct list_head *h)