From: Xiangyu Chen xiangyu.chen@windriver.com
Following series is a backport of CVE-2024-36915
The fix is "nfc: llcp: fix nfc_llcp_setsockopt() unsafe copies" This required 1 extra commit to make sure the picks are clean: net: add copy_safe_from_sockptr() helper
Eric Dumazet (2): net: add copy_safe_from_sockptr() helper nfc: llcp: fix nfc_llcp_setsockopt() unsafe copies
include/linux/sockptr.h | 25 +++++++++++++++++++++++++ net/nfc/llcp_sock.c | 12 ++++++------ 2 files changed, 31 insertions(+), 6 deletions(-)
From: Eric Dumazet edumazet@google.com
[ Upstream commit 6309863b31dd80317cd7d6824820b44e254e2a9c ]
copy_from_sockptr() helper is unsafe, unless callers did the prior check against user provided optlen.
Too many callers get this wrong, lets add a helper to fix them and avoid future copy/paste bugs.
Instead of :
if (optlen < sizeof(opt)) { err = -EINVAL; break; } if (copy_from_sockptr(&opt, optval, sizeof(opt)) { err = -EFAULT; break; }
Use :
err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen); if (err) break;
Signed-off-by: Eric Dumazet edumazet@google.com Link: https://lore.kernel.org/r/20240408082845.3957374-2-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 7a87441c9651 ("nfc: llcp: fix nfc_llcp_setsockopt() unsafe copies") Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Xiangyu Chen xiangyu.chen@windriver.com --- include/linux/sockptr.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)
diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h index bae5e2369b4f..1c1a5d926b17 100644 --- a/include/linux/sockptr.h +++ b/include/linux/sockptr.h @@ -50,11 +50,36 @@ static inline int copy_from_sockptr_offset(void *dst, sockptr_t src, return 0; }
+/* Deprecated. + * This is unsafe, unless caller checked user provided optlen. + * Prefer copy_safe_from_sockptr() instead. + */ static inline int copy_from_sockptr(void *dst, sockptr_t src, size_t size) { return copy_from_sockptr_offset(dst, src, 0, size); }
+/** + * copy_safe_from_sockptr: copy a struct from sockptr + * @dst: Destination address, in kernel space. This buffer must be @ksize + * bytes long. + * @ksize: Size of @dst struct. + * @optval: Source address. (in user or kernel space) + * @optlen: Size of @optval data. + * + * Returns: + * * -EINVAL: @optlen < @ksize + * * -EFAULT: access to userspace failed. + * * 0 : @ksize bytes were copied + */ +static inline int copy_safe_from_sockptr(void *dst, size_t ksize, + sockptr_t optval, unsigned int optlen) +{ + if (optlen < ksize) + return -EINVAL; + return copy_from_sockptr(dst, optval, ksize); +} + static inline int copy_to_sockptr_offset(sockptr_t dst, size_t offset, const void *src, size_t size) {
From: Eric Dumazet edumazet@google.com
[ Upstream commit 7a87441c9651ba37842f4809224aca13a554a26f ]
syzbot reported unsafe calls 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 nfc_llcp_setsockopt+0x6c2/0x850 net/nfc/llcp_sock.c:255 Read of size 4 at addr ffff88801caa1ec3 by task syz-executor459/5078
CPU: 0 PID: 5078 Comm: syz-executor459 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] copy_from_sockptr include/linux/sockptr.h:55 [inline] nfc_llcp_setsockopt+0x6c2/0x850 net/nfc/llcp_sock.c:255 do_sock_setsockopt+0x3b1/0x720 net/socket.c:2311 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xfd/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f7fac07fd89 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff660eb788 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f7fac07fd89 RDX: 0000000000000000 RSI: 0000000000000118 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000020000a80 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Reviewed-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org Link: https://lore.kernel.org/r/20240408082845.3957374-4-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Xiangyu Chen xiangyu.chen@windriver.com --- net/nfc/llcp_sock.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index 645677f84dba..cd0fd26196b8 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -252,10 +252,10 @@ static int nfc_llcp_setsockopt(struct socket *sock, int level, int optname, break; }
- if (copy_from_sockptr(&opt, optval, sizeof(u32))) { - err = -EFAULT; + err = copy_safe_from_sockptr(&opt, sizeof(opt), + optval, optlen); + if (err) break; - }
if (opt > LLCP_MAX_RW) { err = -EINVAL; @@ -274,10 +274,10 @@ static int nfc_llcp_setsockopt(struct socket *sock, int level, int optname, break; }
- if (copy_from_sockptr(&opt, optval, sizeof(u32))) { - err = -EFAULT; + err = copy_safe_from_sockptr(&opt, sizeof(opt), + optval, optlen); + if (err) break; - }
if (opt > LLCP_MAX_MIUX) { err = -EINVAL;
On Tue, Nov 19, 2024 at 10:05:35AM +0800, Xiangyu Chen wrote:
From: Xiangyu Chen xiangyu.chen@windriver.com
Following series is a backport of CVE-2024-36915
The fix is "nfc: llcp: fix nfc_llcp_setsockopt() unsafe copies" This required 1 extra commit to make sure the picks are clean: net: add copy_safe_from_sockptr() helper
Eric Dumazet (2): net: add copy_safe_from_sockptr() helper nfc: llcp: fix nfc_llcp_setsockopt() unsafe copies
include/linux/sockptr.h | 25 +++++++++++++++++++++++++ net/nfc/llcp_sock.c | 12 ++++++------ 2 files changed, 31 insertions(+), 6 deletions(-)
-- 2.43.0
Now queued up, thanks.
greg k-h
linux-stable-mirror@lists.linaro.org
-
Greg KH -
Xiangyu Chen