[syzbot] [net?] kernel BUG in set_ipsecrequest

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 48a97ffc6c82 bpf: Consistently use bpf_rcu_lock_held() eve..
git tree: bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=144d0734580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16f7e5e2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11ecec58580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/87ffd600eff3/disk-48a97ffc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/aa84f0e32430/vmlinux-48a97ffc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/16498048e16c/bzImage-48a97ffc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com

skbuff: skb_over_panic: text:ffffffff8a1fdd63 len:392 put:16 head:ffff888073664d00 data:ffff888073664d00 tail:0x188 end:0x180 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:212!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 6012 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:212
Code: c7 60 10 6e 8c 48 8b 74 24 08 48 8b 54 24 10 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 55 41 57 41 56 e8 6e 54 f5 ff 48 83 c4 20 90 <0f> 0b cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003d5eb68 EFLAGS: 00010282
RAX: 0000000000000088 RBX: dffffc0000000000 RCX: bc84b821dc35fd00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000180 R08: ffffc90003d5e867 R09: 1ffff920007abd0c
R10: dffffc0000000000 R11: fffff520007abd0d R12: ffff8880720b7b50
R13: ffff888073664d00 R14: ffff888073664d00 R15: 0000000000000188
FS: 000055555b9e7500(0000) GS:ffff888125e0c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555b9e7808 CR3: 000000007ead6000 CR4: 00000000003526f0
Call Trace:
<TASK>
skb_over_panic net/core/skbuff.c:217 [inline]
skb_put+0x159/0x210 net/core/skbuff.c:2583
skb_put_zero include/linux/skbuff.h:2788 [inline]
set_ipsecrequest+0x73/0x680 net/key/af_key.c:3532
pfkey_send_migrate+0x11f2/0x1de0 net/key/af_key.c:3636
km_migrate+0x155/0x260 net/xfrm/xfrm_state.c:2838
xfrm_migrate+0x2020/0x2330 net/xfrm/xfrm_policy.c:4698
xfrm_do_migrate+0x796/0x900 net/xfrm/xfrm_user.c:3144
xfrm_user_rcv_msg+0x7a3/0xab0 net/xfrm/xfrm_user.c:3501
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
____sys_sendmsg+0x505/0x830 net/socket.c:2630
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
__sys_sendmsg net/socket.c:2716 [inline]
__do_sys_sendmsg net/socket.c:2721 [inline]
__se_sys_sendmsg net/socket.c:2719 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5fcd58eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe59dd1ab8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5fcd7e5fa0 RCX: 00007f5fcd58eec9
RDX: 0000000000000000 RSI: 0000200000000380 RDI: 0000000000000004
RBP: 00007f5fcd611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5fcd7e5fa0 R14: 00007f5fcd7e5fa0 R15: 0000000000000003
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:212
Code: c7 60 10 6e 8c 48 8b 74 24 08 48 8b 54 24 10 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 55 41 57 41 56 e8 6e 54 f5 ff 48 83 c4 20 90 <0f> 0b cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003d5eb68 EFLAGS: 00010282
RAX: 0000000000000088 RBX: dffffc0000000000 RCX: bc84b821dc35fd00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000180 R08: ffffc90003d5e867 R09: 1ffff920007abd0c
R10: dffffc0000000000 R11: fffff520007abd0d R12: ffff8880720b7b50
R13: ffff888073664d00 R14: ffff888073664d00 R15: 0000000000000188
FS: 000055555b9e7500(0000) GS:ffff888125e0c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555b9e7808 CR3: 000000007ead6000 CR4: 00000000003526f0


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
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(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has bisected this issue to:

commit 14ad6ed30a10afbe91b0749d6378285f4225d482
Author: Paolo Abeni <pab...@redhat.com>
Date: Tue Feb 18 18:29:39 2025 +0000

net: allow small head cache usage with large MAX_SKB_FRAGS values

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=177a35e2580000
start commit: 48a97ffc6c82 bpf: Consistently use bpf_rcu_lock_held() eve..
git tree: bpf-next
final oops: https://syzkaller.appspot.com/x/report.txt?x=14fa35e2580000
console output: https://syzkaller.appspot.com/x/log.txt?x=10fa35e2580000

kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16f7e5e2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11ecec58580000

Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com
Fixes: 14ad6ed30a10 ("net: allow small head cache usage with large MAX_SKB_FRAGS values")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Edward Adam Davis]

When setting the extended skb data for sadb_x_ipsecrequest, the requested
extended data size exceeds the allocated skb data length, triggering the
reported bug.

Because family only supports AF_INET and AF_INET6, other values will cause
pfkey_sockaddr_fill() to fail, which in turn causes set_ipsecrequest() to
fail.

Therefore, a workaround is available here: using a family value of 0 to
resolve the issue of excessively large extended data length.

syzbot reported:

kernel BUG at net/core/skbuff.c:212!

Call Trace:

skb_over_panic net/core/skbuff.c:217 [inline]
skb_put+0x159/0x210 net/core/skbuff.c:2583
skb_put_zero include/linux/skbuff.h:2788 [inline]
set_ipsecrequest+0x73/0x680 net/key/af_key.c:3532

Fixes: 08de61beab8a ("[PFKEYV2]: Extension for dynamic update of endpoint address(es)")
Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4
Signed-off-by: Edward Adam Davis <ead...@qq.com>
---
net/key/af_key.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 2ebde0352245..e658c129b38f 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3526,6 +3526,9 @@ static int set_ipsecrequest(struct sk_buff *skb,
int socklen = pfkey_sockaddr_len(family);
int size_req;

+ if (!family)
+ return -EINVAL;
+
size_req = sizeof(struct sadb_x_ipsecrequest) +
pfkey_sockaddr_pair_size(family);

--
2.43.0

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/key/af_key.c
patch: **** unexpected end of file in patch



Tested on:

commit: d9043c79 Merge tag 'sched_urgent_for_v6.18_rc2' of git..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4

compiler:
patch: https://syzkaller.appspot.com/x/patch.diff?x=17653a14580000

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/key/af_key.c
patch: **** unexpected end of file in patch



Tested on:

commit: d9043c79 Merge tag 'sched_urgent_for_v6.18_rc2' of git..

git tree: upstream

kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4
compiler:

patch: https://syzkaller.appspot.com/x/patch.diff?x=10e21492580000

[syzbot]

patch: https://syzkaller.appspot.com/x/patch.diff?x=16621492580000

[syzbot]

For archival purposes, forwarding an incoming command email to
syzkall...@googlegroups.com.

***

Subject: [PATCH] net: key: Validate address family in set_ipsecrequest()
Author: ssran...@ee.vjti.ac.in

Hi syzbot,

Please test the following patch.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master

Thanks,
Shaurya Rane


From 123c5ac9ba261681b58a6217409c94722fde4249 Mon Sep 17 00:00:00 2001
From: Shaurya Rane <ssran...@ee.vjti.ac.in>
Date: Sun, 19 Oct 2025 23:18:30 +0530
Subject: [PATCH] net: key: Validate address family in set_ipsecrequest()

syzbot reported a kernel BUG in set_ipsecrequest() due to an
skb_over_panic when processing XFRM_MSG_MIGRATE messages.

The root cause is that set_ipsecrequest() does not validate the
address family parameter before using it to calculate buffer sizes.
When an unsupported family value (such as 0) is passed,
pfkey_sockaddr_len() returns 0, leading to incorrect size calculations.

In pfkey_send_migrate(), the buffer size is calculated based on
pfkey_sockaddr_pair_size(), which uses pfkey_sockaddr_len(). When
family=0, this returns 0, so only sizeof(struct sadb_x_ipsecrequest)
(16 bytes) is allocated per entry. However, set_ipsecrequest() is
called multiple times in a loop (once for old_family, once for
new_family, for each migration bundle), repeatedly calling skb_put_zero()
with 16 bytes each time.

This causes the tail pointer to exceed the end pointer of the skb,
triggering skb_over_panic:
tail: 0x188 (392 bytes)
end: 0x180 (384 bytes)

Fix this by validating that pfkey_sockaddr_len() returns a non-zero
value before proceeding with buffer operations. This ensures proper
size calculations and prevents buffer overflow. Checking socklen
instead of just family==0 provides comprehensive validation for all
unsupported address families.

Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4
Fixes: 08de61beab8a ("[PFKEYV2]: Extension for dynamic update of
endpoint address(es)")

Signed-off-by: Shaurya Rane <ssran...@ee.vjti.ac.in>
---
net/key/af_key.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 2ebde0352245..713344c594d4 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3526,6 +3526,10 @@ static int set_ipsecrequest(struct sk_buff *skb,

int socklen = pfkey_sockaddr_len(family);
int size_req;

+ /* Reject invalid/unsupported address families */
+ if (!socklen)

+ return -EINVAL;
+
size_req = sizeof(struct sadb_x_ipsecrequest) +
pfkey_sockaddr_pair_size(family);

--

2.34.1

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/key/af_key.c
patch: **** unexpected end of file in patch



Tested on:

commit: 7361c864 selftests/bpf: Fix list_del() in arena list
git tree: bpf-next

kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4
compiler:

patch: https://syzkaller.appspot.com/x/patch.diff?x=11031492580000

[syzbot]

For archival purposes, forwarding an incoming command email to

linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: [Testing] net: key: Validate address family in set_ipsecrequest()
Author: ssran...@ee.vjti.ac.in

Please test the following patch.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master

Thanks,
Shaurya Rane

From: ssran...@gmail.com

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in set_ipsecrequest

skbuff: skb_over_panic: text:ffffffff8a205d63 len:392 put:16 head:ffff88805b276a40 data:ffff88805b276a40 tail:0x188 end:0x180 dev:<NULL>
------------[ cut here ]------------

kernel BUG at net/core/skbuff.c:212!

Oops: invalid opcode: 0000 [#1] SMP KASAN PTI

CPU: 0 UID: 0 PID: 6444 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:212

Code: c7 60 0e 6e 8c 48 8b 74 24 08 48 8b 54 24 10 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 55 41 57 41 56 e8 4e 50 f5 ff 48 83 c4 20 90 <0f> 0b cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003c06b68 EFLAGS: 00010282
RAX: 0000000000000088 RBX: dffffc0000000000 RCX: 05b0c7e83ffe1100

RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000

RBP: 0000000000000180 R08: ffffc90003c06867 R09: 1ffff92000780d0c
R10: dffffc0000000000 R11: fffff52000780d0d R12: ffff888078c92150
R13: ffff88805b276a40 R14: ffff88805b276a40 R15: 0000000000000188
FS: 00007f2bce8166c0(0000) GS:ffff888125d0b000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f90ed0682d0 CR3: 0000000069384000 CR4: 00000000003526f0
Call Trace:
<TASK>

skb_over_panic net/core/skbuff.c:217 [inline]
skb_put+0x159/0x210 net/core/skbuff.c:2583
skb_put_zero include/linux/skbuff.h:2788 [inline]
set_ipsecrequest+0x73/0x680 net/key/af_key.c:3532

pfkey_send_migrate+0x11f2/0x1de0 net/key/af_key.c:3636
km_migrate+0x155/0x260 net/xfrm/xfrm_state.c:2838
xfrm_migrate+0x2020/0x2330 net/xfrm/xfrm_policy.c:4698
xfrm_do_migrate+0x796/0x900 net/xfrm/xfrm_user.c:3144
xfrm_user_rcv_msg+0x7a3/0xab0 net/xfrm/xfrm_user.c:3501
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
____sys_sendmsg+0x505/0x830 net/socket.c:2630
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
__sys_sendmsg net/socket.c:2716 [inline]
__do_sys_sendmsg net/socket.c:2721 [inline]
__se_sys_sendmsg net/socket.c:2719 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

RIP: 0033:0x7f2bcd98eec9

Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007f2bce816038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2bcdbe5fa0 RCX: 00007f2bcd98eec9

RDX: 0000000000000000 RSI: 0000200000000380 RDI: 0000000000000004

RBP: 00007f2bcda11f91 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007f2bcdbe6038 R14: 00007f2bcdbe5fa0 R15: 00007ffd8b27cbc8

</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:212

Code: c7 60 0e 6e 8c 48 8b 74 24 08 48 8b 54 24 10 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 55 41 57 41 56 e8 4e 50 f5 ff 48 83 c4 20 90 <0f> 0b cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003c06b68 EFLAGS: 00010282
RAX: 0000000000000088 RBX: dffffc0000000000 RCX: 05b0c7e83ffe1100

RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000

RBP: 0000000000000180 R08: ffffc90003c06867 R09: 1ffff92000780d0c
R10: dffffc0000000000 R11: fffff52000780d0d R12: ffff888078c92150
R13: ffff88805b276a40 R14: ffff88805b276a40 R15: 0000000000000188
FS: 00007f2bce8166c0(0000) GS:ffff888125e0b000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 0000200000001f40 CR3: 0000000069384000 CR4: 00000000003526f0

Tested on:

commit: 7361c864 selftests/bpf: Fix list_del() in arena list
git tree: bpf-next

console output: https://syzkaller.appspot.com/x/log.txt?x=12e10e7c580000

kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4

compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Note: no patches were applied.

[syzbot]

> #syz test:

want either no args or 2 args (repo, branch), got 7

> From 2edfc8833e43cdf5ccda8bd5be3da5d1bbdc69c6 Mon Sep 17 00:00:00 2001
> From: clingfei <15991...@qq.com>
> Date: Mon, 20 Oct 2025 13:40:35 +0800
> Subject: [PATCH] fix integer overflow in set_ipsecrequest
> The mp->new_family and mp->old_family is u16, while set_ipsecrequest receives family as uint8_t,
> causing a integer overflow and the later size_req calculation error, which ultimately triggered a
> kernel bug in skb_put.

>
> Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4
>

> ---
> net/key/af_key.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/key/af_key.c b/net/key/af_key.c
> index 2ebde0352245..08f4cde01994 100644
> --- a/net/key/af_key.c
> +++ b/net/key/af_key.c
> @@ -3518,7 +3518,7 @@ static int set_sadb_kmaddress(struct sk_buff *skb, const struct xfrm_kmaddress *

>
> static int set_ipsecrequest(struct sk_buff *skb,

> uint8_t proto, uint8_t mode, int level,
> - uint32_t reqid, uint8_t family,
> + uint32_t reqid, uint16_t family,
> const xfrm_address_t *src, const xfrm_address_t *dst)
> {
> struct sadb_x_ipsecrequest *rq;
> --
> 2.34.1

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: [PATCH] Fix integer overflow in set_ipsecrequest()
Author: clf7...@gmail.com

Hi syzbot,

Please test the following patch.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master

Thanks.

From db24f0985600db1f88d5d2b7420f0707d67ea05a Mon Sep 17 00:00:00 2001
From: clingfei <clf7...@gmail.com>
Date: Mon, 20 Oct 2025 13:48:54 +0800
Subject: [PATCH] fix integer overflow in set_ipsecrequest()

syzbot reported a kernel BUG in set_ipsecrequest() due to an skb_over_panic.

The mp->new_family and mp->old_family is u16, while set_ipsecrequest receives
family as uint8_t, causing a integer overflow and the later size_req calculation

error, which exceeds the size used in alloc_skb, and ultimately triggered the

kernel bug in skb_put.

Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4

Signed-off-by: Cheng Lingfei <clf7...@gmail.com>

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/key/af_key.c
patch: **** unexpected end of file in patch

Tested on:

commit: 7361c864 selftests/bpf: Fix list_del() in arena list
git tree: bpf-next

kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4
compiler:

patch: https://syzkaller.appspot.com/x/patch.diff?x=104b5de2580000

[shaurya]

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

From 123c5ac9ba261681b58a6217409c94722fde4249 Mon Sep 17 00:00:00 2001

From: Shaurya Rane <ssran...@ee.vjti.ac.in>

Date: Sun, 19 Oct 2025 23:18:30 +0530

Subject: [PATCH] net: key: Validate address family in set_ipsecrequest()

syzbot reported a kernel BUG in set_ipsecrequest() due to an

skb_over_panic when processing XFRM_MSG_MIGRATE messages.

The root cause is that set_ipsecrequest() does not validate the

address family parameter before using it to calculate buffer sizes.

When an unsupported family value (such as 0) is passed,

pfkey_sockaddr_len() returns 0, leading to incorrect size calculations.

In pfkey_send_migrate(), the buffer size is calculated based on

pfkey_sockaddr_pair_size(), which uses pfkey_sockaddr_len(). When

family=0, this returns 0, so only sizeof(struct sadb_x_ipsecrequest)

(16 bytes) is allocated per entry. However, set_ipsecrequest() is

called multiple times in a loop (once for old_family, once for

new_family, for each migration bundle), repeatedly calling skb_put_zero()

with 16 bytes each time.

This causes the tail pointer to exceed the end pointer of the skb,

triggering skb_over_panic:

tail: 0x188 (392 bytes)

end: 0x180 (384 bytes)

Fix this by validating that pfkey_sockaddr_len() returns a non-zero

value before proceeding with buffer operations. This ensures proper

size calculations and prevents buffer overflow. Checking socklen

instead of just family==0 provides comprehensive validation for all

unsupported address families.

Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com

Closes: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4

Fixes: 08de61beab8a ("[PFKEYV2]: Extension for dynamic update of endpoint address(es)")

Signed-off-by: Shaurya Rane <ssran...@ee.vjti.ac.in>

---

net/key/af_key.c | 4 ++++

1 file changed, 4 insertions(+)

diff --git a/net/key/af_key.c b/net/key/af_key.c

index 2ebde0352245..713344c594d4 100644

--- a/net/key/af_key.c

+++ b/net/key/af_key.c

@@ -3526,6 +3526,10 @@ static int set_ipsecrequest(struct sk_buff *skb,

[1599101385]

#syz test

From 2edfc8833e43cdf5ccda8bd5be3da5d1bbdc69c6 Mon Sep 17 00:00:00 2001
From: clingfei <15991...@qq.com>
Date: Mon, 20 Oct 2025 13:40:35 +0800

Subject: [PATCH] fix integer overflow in set_ipsecrequest

The mp->new_family and mp->old_family is u16, while set_ipsecrequest receives family as uint8_t, 

causing a integer overflow and the later size_req calculation error, which ultimately triggered a 
kernel bug in skb_put.

Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4

---

 net/key/af_key.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 2ebde0352245..08f4cde01994 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3518,7 +3518,7 @@ static int set_sadb_kmaddress(struct sk_buff *skb, const struct xfrm_kmaddress *

 static int set_ipsecrequest(struct sk_buff *skb,

[15991...@qq.com]

[shaurya]

#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

From 123c5ac9ba261681b58a6217409c94722fde4249 Mon Sep 17 00:00:00 2001

Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4

Fixes: 08de61beab8a ("[PFKEYV2]: Extension for dynamic update of
endpoint address(es)")

Signed-off-by: Shaurya Rane <ssran...@ee.vjti.ac.in>
---
 net/key/af_key.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 2ebde0352245..713344c594d4 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3526,6 +3526,10 @@ static int set_ipsecrequest(struct sk_buff *skb,

[ssran...@gmail.com]

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

[syzbot]

patch: https://syzkaller.appspot.com/x/patch.diff?x=16776b04580000

[clingfei]

syzbot <syzbot+be97dd...@syzkaller.appspotmail.com>
于2025年10月20日周一 15:36写道：

Hi syzbot,

Please test the following patch.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master

Thanks.

From 6dc2deb09faf7d53707cc9e75e175b09644fd181 Mon Sep 17 00:00:00 2001
From: clingfei <clf7...@gmail.com>
Date: Mon, 20 Oct 2025 13:48:54 +0800

Subject: [PATCH] fix integer overflow in set_ipsecrequest

syzbot reported a kernel BUG in set_ipsecrequest() due to an skb_over_panic.

The mp->new_family and mp->old_family is u16, while set_ipsecrequest receives
family as uint8_t, causing a integer overflow and the later size_req
calculation

error, which exceeds the size used in alloc_skb, and ultimately triggered the
kernel bug in skb_put.

Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4

Signed-off-by: Cheng Lingfei <clf7...@gmail.com>

---
net/key/af_key.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 2ebde0352245..08f4cde01994 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c

@@ -3518,7 +3518,7 @@ static int set_sadb_kmaddress(struct sk_buff
*skb, const struct xfrm_kmaddress *

static int set_ipsecrequest(struct sk_buff *skb,

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: Re: [syzbot] [net?] kernel BUG in set_ipsecrequest
Author: clf7...@gmail.com

syzbot <syzbot+be97dd...@syzkaller.appspotmail.com>
于2025年10月20日周一 15:48写道：

>
> Hello,
>
> syzbot tried to test the proposed patch but the build/boot failed:
>
> failed to apply patch:
> checking file net/key/af_key.c
> patch: **** unexpected end of file in patch
>
>
>
> Tested on:
>
> commit: 7361c864 selftests/bpf: Fix list_del() in arena list
> git tree: bpf-next

> kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
> dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4
> compiler:

> patch: https://syzkaller.appspot.com/x/patch.diff?x=16776b04580000

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/key/af_key.c
patch: **** unexpected end of file in patch



Tested on:

commit: 7361c864 selftests/bpf: Fix list_del() in arena list
git tree: bpf-next
kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4
compiler:

patch: https://syzkaller.appspot.com/x/patch.diff?x=122d3c58580000

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject:

Author: clf7...@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+be97dd...@syzkaller.appspotmail.com
Tested-by: syzbot+be97dd...@syzkaller.appspotmail.com

Tested on:

commit: 7361c864 selftests/bpf: Fix list_del() in arena list
git tree: bpf-next

console output: https://syzkaller.appspot.com/x/log.txt?x=1089f52f980000

kernel config: https://syzkaller.appspot.com/x/.config?x=9ad7b090a18654a7
dashboard link: https://syzkaller.appspot.com/bug?extid=be97dd4da14ae88b6ba4

compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=12bf83cd980000

Note: testing is done by a robot and is best-effort only.