diff options
| -rw-r--r-- | fs/exec.c | 26 | ||||
| -rw-r--r-- | fs/exec_test.c | 2 | ||||
| -rw-r--r-- | include/linux/binfmts.h | 2 |
3 files changed, 23 insertions, 7 deletions
diff --git a/fs/exec.c b/fs/exec.c index c3bec126505b..b7bc63bfb907 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -486,6 +486,23 @@ static int count_strings_kernel(const char *const *argv) return i; } +static inline int bprm_set_stack_limit(struct linux_binprm *bprm, + unsigned long limit) +{ +#ifdef CONFIG_MMU + bprm->argmin = bprm->p - limit; +#endif + return 0; +} +static inline bool bprm_hit_stack_limit(struct linux_binprm *bprm) +{ +#ifdef CONFIG_MMU + return bprm->p < bprm->argmin; +#else + return false; +#endif +} + /* * Calculate bprm->argmin from: * - _STK_LIM @@ -532,8 +549,7 @@ static int bprm_stack_limits(struct linux_binprm *bprm) return -E2BIG; limit -= ptr_size; - bprm->argmin = bprm->p - limit; - return 0; + return bprm_set_stack_limit(bprm, limit); } /* @@ -571,10 +587,8 @@ static int copy_strings(int argc, struct user_arg_ptr argv, pos = bprm->p; str += len; bprm->p -= len; -#ifdef CONFIG_MMU - if (bprm->p < bprm->argmin) + if (bprm_hit_stack_limit(bprm)) goto out; -#endif while (len > 0) { int offset, bytes_to_copy; @@ -649,7 +663,7 @@ int copy_string_kernel(const char *arg, struct linux_binprm *bprm) /* We're going to work our way backwards. */ arg += len; bprm->p -= len; - if (IS_ENABLED(CONFIG_MMU) && bprm->p < bprm->argmin) + if (bprm_hit_stack_limit(bprm)) return -E2BIG; while (len > 0) { diff --git a/fs/exec_test.c b/fs/exec_test.c index 32a90c6f47e7..8fea0bf0b7f5 100644 --- a/fs/exec_test.c +++ b/fs/exec_test.c @@ -96,7 +96,9 @@ static void exec_test_bprm_stack_limits(struct kunit *test) rc = bprm_stack_limits(&bprm); KUNIT_EXPECT_EQ_MSG(test, rc, result->expected_rc, "on loop %d", i); +#ifdef CONFIG_MMU KUNIT_EXPECT_EQ_MSG(test, bprm.argmin, result->expected_argmin, "on loop %d", i); +#endif } } diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 70f97f685bff..e6c00e860951 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -19,13 +19,13 @@ struct linux_binprm { #ifdef CONFIG_MMU struct vm_area_struct *vma; unsigned long vma_pages; + unsigned long argmin; /* rlimit marker for copy_strings() */ #else # define MAX_ARG_PAGES 32 struct page *page[MAX_ARG_PAGES]; #endif struct mm_struct *mm; unsigned long p; /* current top of mem */ - unsigned long argmin; /* rlimit marker for copy_strings() */ unsigned int /* Should an execfd be passed to userspace? */ have_execfd:1, |