diff mbox series

[5/5] xfrm: fix one more kernel-infoleak in algo dumping

Message ID 20241022092226.654370-6-steffen.klassert@secunet.com (mailing list archive)
State Accepted
Commit 6889cd2a93e1e3606b3f6e958aa0924e836de4d2
Delegated to: Netdev Maintainers
Headers show
Series [1/5] xfrm: extract dst lookup parameters into a struct | expand

Checks

Context Check Description
netdev/series_format warning Pull request is its own cover letter; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers fail 1 blamed authors not CCed: antony.antony@secunet.com; 3 maintainers not CCed: edumazet@google.com pabeni@redhat.com antony.antony@secunet.com
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 19 this patch: 19
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 10 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-10-23--12-00 (tests: 777)

Commit Message

Steffen Klassert Oct. 22, 2024, 9:22 a.m. UTC 
From: Petr Vaganov <p.vaganov@ideco.ru>

During fuzz testing, the following issue was discovered:

BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x598/0x2a30
 _copy_to_iter+0x598/0x2a30
 __skb_datagram_iter+0x168/0x1060
 skb_copy_datagram_iter+0x5b/0x220
 netlink_recvmsg+0x362/0x1700
 sock_recvmsg+0x2dc/0x390
 __sys_recvfrom+0x381/0x6d0
 __x64_sys_recvfrom+0x130/0x200
 x64_sys_call+0x32c8/0x3cc0
 do_syscall_64+0xd8/0x1c0
 entry_SYSCALL_64_after_hwframe+0x79/0x81

Uninit was stored to memory at:
 copy_to_user_state_extra+0xcc1/0x1e00
 dump_one_state+0x28c/0x5f0
 xfrm_state_walk+0x548/0x11e0
 xfrm_dump_sa+0x1e0/0x840
 netlink_dump+0x943/0x1c40
 __netlink_dump_start+0x746/0xdb0
 xfrm_user_rcv_msg+0x429/0xc00
 netlink_rcv_skb+0x613/0x780
 xfrm_netlink_rcv+0x77/0xc0
 netlink_unicast+0xe90/0x1280
 netlink_sendmsg+0x126d/0x1490
 __sock_sendmsg+0x332/0x3d0
 ____sys_sendmsg+0x863/0xc30
 ___sys_sendmsg+0x285/0x3e0
 __x64_sys_sendmsg+0x2d6/0x560
 x64_sys_call+0x1316/0x3cc0
 do_syscall_64+0xd8/0x1c0
 entry_SYSCALL_64_after_hwframe+0x79/0x81

Uninit was created at:
 __kmalloc+0x571/0xd30
 attach_auth+0x106/0x3e0
 xfrm_add_sa+0x2aa0/0x4230
 xfrm_user_rcv_msg+0x832/0xc00
 netlink_rcv_skb+0x613/0x780
 xfrm_netlink_rcv+0x77/0xc0
 netlink_unicast+0xe90/0x1280
 netlink_sendmsg+0x126d/0x1490
 __sock_sendmsg+0x332/0x3d0
 ____sys_sendmsg+0x863/0xc30
 ___sys_sendmsg+0x285/0x3e0
 __x64_sys_sendmsg+0x2d6/0x560
 x64_sys_call+0x1316/0x3cc0
 do_syscall_64+0xd8/0x1c0
 entry_SYSCALL_64_after_hwframe+0x79/0x81

Bytes 328-379 of 732 are uninitialized
Memory access of size 732 starts at ffff88800e18e000
Data copied to user address 00007ff30f48aff0

CPU: 2 PID: 18167 Comm: syz-executor.0 Not tainted 6.8.11 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014

Fixes copying of xfrm algorithms where some random
data of the structure fields can end up in userspace.
Padding in structures may be filled with random (possibly sensitve)
data and should never be given directly to user-space.

A similar issue was resolved in the commit
8222d5910dae ("xfrm: Zero padding when dumping algos and encap")

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: c7a5899eb26e ("xfrm: redact SA secret with lockdown confidentiality")
Cc: stable@vger.kernel.org
Co-developed-by: Boris Tonofa <b.tonofa@ideco.ru>
Signed-off-by: Boris Tonofa <b.tonofa@ideco.ru>
Signed-off-by: Petr Vaganov <p.vaganov@ideco.ru>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_user.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 8d06a37adbd9..eb146f574bbd 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1102,7 +1102,9 @@  static int copy_to_user_auth(struct xfrm_algo_auth *auth, struct sk_buff *skb)
 	if (!nla)
 		return -EMSGSIZE;
 	ap = nla_data(nla);
-	memcpy(ap, auth, sizeof(struct xfrm_algo_auth));
+	strscpy_pad(ap->alg_name, auth->alg_name, sizeof(ap->alg_name));
+	ap->alg_key_len = auth->alg_key_len;
+	ap->alg_trunc_len = auth->alg_trunc_len;
 	if (redact_secret && auth->alg_key_len)
 		memset(ap->alg_key, 0, (auth->alg_key_len + 7) / 8);
 	else