6.13-stable review patch. If anyone has any objections, please let me know.
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From: Oleg Nesterov oleg@redhat.com
[ Upstream commit b37778bec82ba82058912ca069881397197cd3d5 ]
Depending on CONFIG_HAVE_ARCH_SECCOMP_FILTER, __secure_computing(NULL) will crash or not. This is not consistent/safe, especially considering that after the previous change __secure_computing(sd) is always called with sd == NULL.
Fortunately, if CONFIG_HAVE_ARCH_SECCOMP_FILTER=n, __secure_computing() has no callers, these architectures use secure_computing_strict(). Yet it make sense make __secure_computing(NULL) safe in this case.
Note also that with this change we can unexport secure_computing_strict() and change the current callers to use __secure_computing(NULL).
Fixes: 8cf8dfceebda ("seccomp: Stub for !HAVE_ARCH_SECCOMP_FILTER") Signed-off-by: Oleg Nesterov oleg@redhat.com Reviewed-by: Linus Walleij linus.walleij@linaro.org Link: https://lore.kernel.org/r/20250128150307.GA15325@redhat.com Signed-off-by: Kees Cook kees@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/seccomp.h | 8 ++------ kernel/seccomp.c | 14 ++++++++++---- 2 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/include/linux/seccomp.h b/include/linux/seccomp.h index e45531455d3bb..d55949071c30e 100644 --- a/include/linux/seccomp.h +++ b/include/linux/seccomp.h @@ -22,8 +22,9 @@ #include <linux/atomic.h> #include <asm/seccomp.h>
-#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER extern int __secure_computing(const struct seccomp_data *sd); + +#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER static inline int secure_computing(void) { if (unlikely(test_syscall_work(SECCOMP))) @@ -32,11 +33,6 @@ static inline int secure_computing(void) } #else extern void secure_computing_strict(int this_syscall); -static inline int __secure_computing(const struct seccomp_data *sd) -{ - secure_computing_strict(sd->nr); - return 0; -} #endif
extern long prctl_get_seccomp(void); diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 0cd1f8b5a102e..ec58f7cc0e94d 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -29,13 +29,11 @@ #include <linux/syscalls.h> #include <linux/sysctl.h>
+#include <asm/syscall.h> + /* Not exposed in headers: strictly internal use only. */ #define SECCOMP_MODE_DEAD (SECCOMP_MODE_FILTER + 1)
-#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER -#include <asm/syscall.h> -#endif - #ifdef CONFIG_SECCOMP_FILTER #include <linux/file.h> #include <linux/filter.h> @@ -1074,6 +1072,14 @@ void secure_computing_strict(int this_syscall) else BUG(); } +int __secure_computing(const struct seccomp_data *sd) +{ + int this_syscall = sd ? sd->nr : + syscall_get_nr(current, current_pt_regs()); + + secure_computing_strict(this_syscall); + return 0; +} #else
#ifdef CONFIG_SECCOMP_FILTER