aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAKASHI Takahiro <takahiro.akashi@linaro.org>2013-10-03 06:47:44 +0100
committerMark Brown <broonie@linaro.org>2014-05-14 12:16:55 +0100
commitaf68cb6b43a9f32f0143e69e80d17802247818ee (patch)
treefcc63a5b5b8d1b7b4041c915fea32d07a28487bf
parent47b1e20b206944ea097b775e0e4a569f8bdeeb7c (diff)
downloadlinux-linaro-stable-af68cb6b43a9f32f0143e69e80d17802247818ee.tar.gz
arm64: check for number of arguments in syscall_get/set_arguments()
commit 7b22c03536a539142f931815528d55df455ffe2d upstream. In ftrace_syscall_enter(), syscall_get_arguments(..., 0, n, ...) if (i == 0) { <handle orig_x0> ...; 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(). Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> (cherry picked from commit e2956ef5b5ddb3ede70962afe9297d8340787fa6) Signed-off-by: Mark Brown <broonie@linaro.org>
-rw-r--r--arch/arm64/include/asm/syscall.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index 89c047f9a971..70ba9d4ee978 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -59,6 +59,9 @@ 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;
@@ -82,6 +85,9 @@ 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);