syzbot ci has tested the following series [v2] virtio-net: add flow filter for receive timestamps https://lore.kernel.org/all/20260129-v6-7-topic-virtio-net-ptp-v2-0-30a27dc52...@pengutronix.de * [PATCH RFC v2 1/2] tun: support rx-tstamp * [PATCH RFC v2 2/2] virtio-net: support receive timestamp
and found the following issue: WARNING in __copy_overflow Full report is available here: https://ci.syzbot.org/series/0b35c8c9-603b-4126-ac04-0095faadb2f5 *** WARNING in __copy_overflow tree: net-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net-next.git base: ffeafa65b2b26df2f5b5a6118d3174f17bd12ec5 arch: amd64 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 config: https://ci.syzbot.org/builds/d8316da2-2688-4d74-bbf4-e8412e24d106/config C repro: https://ci.syzbot.org/findings/96af937a-787b-4fd5-baef-529fc80e0bb7/c_repro syz repro: https://ci.syzbot.org/findings/96af937a-787b-4fd5-baef-529fc80e0bb7/syz_repro ------------[ cut here ]------------ Buffer overflow detected (32 < 1840)! WARNING: mm/maccess.c:234 at __copy_overflow+0x17/0x30 mm/maccess.c:234, CPU#0: syz.0.17/5993 Modules linked in: CPU: 0 UID: 0 PID: 5993 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:__copy_overflow+0x1c/0x30 mm/maccess.c:234 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 48 89 f3 89 fd e8 60 b1 c4 ff 48 8d 3d 39 25 d5 0d 89 ee 48 89 da <67> 48 0f b9 3a 5b 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 RSP: 0018:ffffc90003b97888 EFLAGS: 00010293 RAX: ffffffff81fdcf50 RBX: 0000000000000730 RCX: ffff88810ccd9d40 RDX: 0000000000000730 RSI: 0000000000000020 RDI: ffffffff8fd2f490 RBP: 0000000000000020 R08: ffffffff8fcec777 R09: 1ffffffff1f9d8ee R10: dffffc0000000000 R11: ffffffff81742230 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000730 R15: 1ffff92000772f30 FS: 00007f08c446a6c0(0000) GS:ffff88818e32d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f08c4448ff8 CR3: 000000010cec2000 CR4: 00000000000006f0 Call Trace: <TASK> copy_overflow include/linux/ucopysize.h:41 [inline] check_copy_size include/linux/ucopysize.h:50 [inline] copy_to_iter include/linux/uio.h:219 [inline] tun_put_user drivers/net/tun.c:2089 [inline] tun_do_read+0x1f44/0x28a0 drivers/net/tun.c:2190 tun_chr_read_iter+0x13b/0x260 drivers/net/tun.c:2214 do_iter_readv_writev+0x619/0x8c0 fs/read_write.c:-1 vfs_readv+0x288/0x840 fs/read_write.c:1018 do_readv+0x154/0x2e0 fs/read_write.c:1080 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08c359acb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f08c446a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 00007f08c3815fa0 RCX: 00007f08c359acb9 RDX: 0000000000000002 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007f08c3608bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f08c3816038 R14: 00007f08c3815fa0 R15: 00007fff6491da78 </TASK> ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: f3 0f 1e fa endbr64 12: 55 push %rbp 13: 53 push %rbx 14: 48 89 f3 mov %rsi,%rbx 17: 89 fd mov %edi,%ebp 19: e8 60 b1 c4 ff call 0xffc4b17e 1e: 48 8d 3d 39 25 d5 0d lea 0xdd52539(%rip),%rdi # 0xdd5255e 25: 89 ee mov %ebp,%esi 27: 48 89 da mov %rbx,%rdx * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 5b pop %rbx 30: 5d pop %rbp 31: c3 ret 32: cc int3 33: cc int3 34: cc int3 35: cc int3 36: cc int3 37: cc int3 38: cc int3 39: cc int3 3a: cc int3 3b: cc int3 3c: cc int3 3d: cc int3 3e: 90 nop 3f: 90 nop *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: [email protected] --- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at [email protected].

