From 1eec6cd08b4feb72a73aff468ab72bdd21e1dc61 Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Tue, 16 Aug 2011 09:54:54 +0800 Subject: [PATCH] MIPS: Compat: Use 32-bit wrapper for compat_sys_futex. We can't trust userspace to pass signed-extend arguments. Not correctly sign-extended arguments to futex-wait result in architecturally undefined operation of 32-bit arithmetic instructions. For example, if 'val' is too big and bit-31 is 1, the caller may enter endless loop at: futex_wait_setup() { ... if (uval != val) { queue_unlock(q, *hb); ret = -EWOULDBLOCK; ... } Signed-off-by: Yong Zhang To: linux-mips@linux-mips.org To: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/2714/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/linux32.c | 7 +++++++ arch/mips/kernel/scall64-n32.S | 2 +- arch/mips/kernel/scall64-o32.S | 2 +- 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c index 876a75c..922a554 100644 --- a/arch/mips/kernel/linux32.c +++ b/arch/mips/kernel/linux32.c @@ -349,3 +349,10 @@ SYSCALL_DEFINE6(32_fanotify_mark, int, fanotify_fd, unsigned int, flags, return sys_fanotify_mark(fanotify_fd, flags, merge_64(a3, a4), dfd, pathname); } + +SYSCALL_DEFINE6(32_futex, u32 __user *, uaddr, int, op, u32, val, + struct compat_timespec __user *, utime, u32 __user *, uaddr2, + u32, val3) +{ + return compat_sys_futex(uaddr, op, val, utime, uaddr2, val3); +} diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S index f9296e8..6de1f59 100644 --- a/arch/mips/kernel/scall64-n32.S +++ b/arch/mips/kernel/scall64-n32.S @@ -315,7 +315,7 @@ EXPORT(sysn32_call_table) PTR sys_fremovexattr PTR sys_tkill PTR sys_ni_syscall - PTR compat_sys_futex + PTR sys_32_futex PTR compat_sys_sched_setaffinity /* 6195 */ PTR compat_sys_sched_getaffinity PTR sys_cacheflush diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S index 4d7c982..1d81316 100644 --- a/arch/mips/kernel/scall64-o32.S +++ b/arch/mips/kernel/scall64-o32.S @@ -441,7 +441,7 @@ sys_call_table: PTR sys_fremovexattr /* 4235 */ PTR sys_tkill PTR sys_sendfile64 - PTR compat_sys_futex + PTR sys_32_futex PTR compat_sys_sched_setaffinity PTR compat_sys_sched_getaffinity /* 4240 */ PTR compat_sys_io_setup -- 2.7.4