path: root/arch
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authorAKASHI Takahiro <takahiro.akashi@linaro.org>2013-10-09 15:58:29 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-10-13 18:54:33 +0100
commit3c1532df5c1b54b5f6246cdef94eeb73a39fe43a (patch)
tree305121d41606b825c069647564d7877faf8d75e3 /arch
parentbc41b8724f24b9a27d1dcc6c974b8f686b38d554 (diff)
ARM: 7851/1: check for number of arguments in syscall_get/set_arguments()
In ftrace_syscall_enter(), syscall_get_arguments(..., 0, n, ...) if (i == 0) { <handle ORIG_r0> ...; n--;} memcpy(..., n * sizeof(args[0])); If 'number of arguments(n)' is zero and 'argument index(i)' is also zero in syscall_get_arguments(), none of arguments should be copied by memcpy(). Otherwise 'n--' can be a big positive number and unexpected amount of data will be copied. Tracing system calls which take no argument, say sync(void), may hit this case and eventually make the system corrupted. This patch fixes the issue both in syscall_get_arguments() and syscall_set_arguments(). Cc: <stable@vger.kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/include/asm/syscall.h b/arch/arm/include/asm/syscall.h
index f1d96d4e809..73ddd7239b3 100644
--- a/arch/arm/include/asm/syscall.h
+++ b/arch/arm/include/asm/syscall.h
@@ -57,6 +57,9 @@ static inline void syscall_get_arguments(struct task_struct *task,
unsigned int i, unsigned int n,
unsigned long *args)
+ if (n == 0)
+ return;
if (i + n > SYSCALL_MAX_ARGS) {
unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
@@ -81,6 +84,9 @@ static inline void syscall_set_arguments(struct task_struct *task,
unsigned int i, unsigned int n,
const unsigned long *args)
+ if (n == 0)
+ return;
if (i + n > SYSCALL_MAX_ARGS) {
pr_warning("%s called with max args %d, handling only %d\n",
__func__, i + n, SYSCALL_MAX_ARGS);