From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- scripts/ssl-common.h | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 scripts/ssl-common.h (limited to 'scripts/ssl-common.h') diff --git a/scripts/ssl-common.h b/scripts/ssl-common.h new file mode 100644 index 000000000..2db0e1811 --- /dev/null +++ b/scripts/ssl-common.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ +/* + * SSL helper functions shared by sign-file and extract-cert. + */ + +static void drain_openssl_errors(int l, int silent) +{ + const char *file; + char buf[120]; + int e, line; + + if (ERR_peek_error() == 0) + return; + if (!silent) + fprintf(stderr, "At main.c:%d:\n", l); + + while ((e = ERR_peek_error_line(&file, &line))) { + ERR_error_string(e, buf); + if (!silent) + fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line); + ERR_get_error(); + } +} + +#define ERR(cond, fmt, ...) \ + do { \ + bool __cond = (cond); \ + drain_openssl_errors(__LINE__, 0); \ + if (__cond) { \ + errx(1, fmt, ## __VA_ARGS__); \ + } \ + } while (0) -- cgit v1.3.1