ipc/shm: Fix order of parameters when calling copy_compat_shmid_to_user
authorWill Deacon <will.deacon@arm.com>
Mon, 18 Sep 2017 16:47:38 +0000 (17:47 +0100)
committerAl Viro <viro@zeniv.linux.org.uk>
Thu, 21 Sep 2017 03:27:48 +0000 (23:27 -0400)
commit58aff0af757356065f33290d96a9cd46dfbcae88
treee4bd9e751d8a67be3ba510d52f9decf5e7d7a2d3
parenta90bcb86ae700c12432446c4aa1819e7b8e172ec
ipc/shm: Fix order of parameters when calling copy_compat_shmid_to_user

Commit 553f770ef71b ("ipc: move compat shmctl to native") moved the
compat IPC syscall handling into ipc/shm.c and refactored the struct
accessors in the process. Unfortunately, the call to
copy_compat_shmid_to_user when handling a compat {IPC,SHM}_STAT command
gets the arguments the wrong way round, passing a kernel stack address
as the user buffer (destination) and the user buffer as the kernel stack
address (source).

This patch fixes the parameter ordering so the buffers are accessed
correctly.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ipc/shm.c