From 138b787804f4a10417618e8d1e6e2700539fd88c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 8 Apr 2024 08:28:44 +0000 Subject: [PATCH] mISDN: fix MISDN_TIME_STAMP handling syzbot reports one unsafe call to copy_from_sockptr() [1] Use copy_safe_from_sockptr() instead. [1] BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline] BUG: KASAN: slab-out-of-bounds in data_sock_setsockopt+0x46c/0x4cc drivers/isdn/mISDN/socket.c:417 Read of size 4 at addr ffff0000c6d54083 by task syz-executor406/6167 CPU: 1 PID: 6167 Comm: syz-executor406 Not tainted 6.8.0-rc7-syzkaller-g707081b61156 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x178/0x518 mm/kasan/report.c:488 kasan_report+0xd8/0x138 mm/kasan/report.c:601 __asan_report_load_n_noabort+0x1c/0x28 mm/kasan/report_generic.c:391 copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] copy_from_sockptr include/linux/sockptr.h:55 [inline] data_sock_setsockopt+0x46c/0x4cc drivers/isdn/mISDN/socket.c:417 do_sock_setsockopt+0x2a0/0x4e0 net/socket.c:2311 __sys_setsockopt+0x128/0x1a8 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __arm64_sys_setsockopt+0xb8/0xd4 net/socket.c:2340 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 Fixes: 1b2b03f8e514 ("Add mISDN core files") Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Karsten Keil Link: https://lore.kernel.org/r/20240408082845.3957374-3-edumazet@google.com Signed-off-by: Jakub Kicinski --- drivers/isdn/mISDN/socket.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c index 2776ca5fc33f..b215b28cad7b 100644 --- a/drivers/isdn/mISDN/socket.c +++ b/drivers/isdn/mISDN/socket.c @@ -401,23 +401,23 @@ data_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) } static int data_sock_setsockopt(struct socket *sock, int level, int optname, - sockptr_t optval, unsigned int len) + sockptr_t optval, unsigned int optlen) { struct sock *sk = sock->sk; int err = 0, opt = 0; if (*debug & DEBUG_SOCKET) printk(KERN_DEBUG "%s(%p, %d, %x, optval, %d)\n", __func__, sock, - level, optname, len); + level, optname, optlen); lock_sock(sk); switch (optname) { case MISDN_TIME_STAMP: - if (copy_from_sockptr(&opt, optval, sizeof(int))) { - err = -EFAULT; + err = copy_safe_from_sockptr(&opt, sizeof(opt), + optval, optlen); + if (err) break; - } if (opt) _pms(sk)->cmask |= MISDN_TIME_STAMP;