From 58aff0af757356065f33290d96a9cd46dfbcae88 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 18 Sep 2017 17:47:38 +0100 Subject: [PATCH] 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 Cc: Andrew Morton Signed-off-by: Will Deacon Signed-off-by: Al Viro --- ipc/shm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ipc/shm.c b/ipc/shm.c index 1b3adfe3c60e..1e2b1692ba2c 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1237,7 +1237,7 @@ COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr) err = shmctl_stat(ns, shmid, cmd, &sem64); if (err < 0) return err; - if (copy_compat_shmid_to_user(&sem64, uptr, version)) + if (copy_compat_shmid_to_user(uptr, &sem64, version)) err = -EFAULT; return err;