diff options
Diffstat (limited to 'mm/usercopy.c')
| -rw-r--r-- | mm/usercopy.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/mm/usercopy.c b/mm/usercopy.c index 5df1e68d4585..8006baa4caac 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -58,11 +58,25 @@ static noinline int check_stack_object(const void *obj, unsigned long len) return GOOD_STACK; } -static void report_usercopy(unsigned long len, bool to_user, const char *type) +/* + * If this function is reached, then CONFIG_HARDENED_USERCOPY has found an + * unexpected state during a copy_from_user() or copy_to_user() call. + * There are several checks being performed on the buffer by the + * __check_object_size() function. Normal stack buffer usage should never + * trip the checks, and kernel text addressing will always trip the check. + * For cache objects, copies must be within the object size. + */ +void __noreturn usercopy_abort(const char *name, const char *detail, + bool to_user, unsigned long offset, + unsigned long len) { - pr_emerg("kernel memory %s attempt detected %s '%s' (%lu bytes)\n", - to_user ? "exposure" : "overwrite", - to_user ? "from" : "to", type ? : "unknown", len); + pr_emerg("Kernel memory %s attempt detected %s %s%s%s%s (offset %lu, size %lu)!\n", + to_user ? "exposure" : "overwrite", + to_user ? "from" : "to", + name ? : "unknown?!", + detail ? " '" : "", detail ? : "", detail ? "'" : "", + offset, len); + /* * For greater effect, it would be nice to do do_group_exit(), * but BUG() actually hooks all the lock-breaking and per-arch @@ -260,6 +274,6 @@ void __check_object_size(const void *ptr, unsigned long n, bool to_user) return; report: - report_usercopy(n, to_user, err); + usercopy_abort(err, NULL, to_user, 0, n); } EXPORT_SYMBOL(__check_object_size); |