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* [PATCH] vdpa: don't free reply skb after genlmsg_reply()
@ 2026-03-12 11:04 Paul Moses
  2026-03-17  1:22 ` Paul Moses
  0 siblings, 1 reply; 4+ messages in thread
From: Paul Moses @ 2026-03-12 11:04 UTC (permalink / raw)
  To: Michael S . Tsirkin, Jason Wang, Xuan Zhuo, Eugenio Pérez,
	Eli Cohen, Parav Pandit
  Cc: virtualization, linux-kernel, Paul Moses, stable

genlmsg_reply() hands the reply skb to netlink, and
netlink_unicast() consumes it on all return paths, whether the
skb is queued successfully or freed on an error path.

vdpa_nl_cmd_dev_config_get_doit() currently jumps to nlmsg_free(msg)
after genlmsg_reply() fails, which can hit the same skb twice.

Return the genlmsg_reply() error directly and keep nlmsg_free()
only for pre-reply failures.

Fixes: ad69dd0bf26b ("vdpa: Introduce query of device config layout")
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moses <p@1g4.org>
---
 drivers/vdpa/vdpa.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 34874beb0152e..702d3a7772219 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -1352,15 +1352,19 @@ static int vdpa_nl_cmd_dev_config_get_doit(struct sk_buff *skb, struct genl_info
 	}
 	err = vdpa_dev_config_fill(vdev, msg, info->snd_portid, info->snd_seq,
 				   0, info->extack);
-	if (!err)
-		err = genlmsg_reply(msg, info);
+	if (err)
+		goto mdev_err;
+
+	put_device(dev);
+	up_read(&vdpa_dev_lock);
+
+	return genlmsg_reply(msg, info);
 
 mdev_err:
 	put_device(dev);
 dev_err:
 	up_read(&vdpa_dev_lock);
-	if (err)
-		nlmsg_free(msg);
+	nlmsg_free(msg);
 	return err;
 }
 
-- 
2.53.GIT



^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] vdpa: don't free reply skb after genlmsg_reply()
  2026-03-12 11:04 [PATCH] vdpa: don't free reply skb after genlmsg_reply() Paul Moses
@ 2026-03-17  1:22 ` Paul Moses
  2026-03-20 21:11   ` Paul Moses
  0 siblings, 1 reply; 4+ messages in thread
From: Paul Moses @ 2026-03-17  1:22 UTC (permalink / raw)
  To: Michael S . Tsirkin, Jason Wang, Xuan Zhuo, Eugenio Pérez,
	Eli Cohen, Parav Pandit
  Cc: virtualization, linux-kernel, Paul Moses, stable

Now that I've wrapped up elsewhere, I can focus on this. Let me 
know if there's any questions.

Thanks,
Paul

[    0.716942] ------------[ cut here ]------------
[    0.717160] refcount_t: underflow; use-after-free.
[    0.717356] WARNING: CPU: 2 PID: 138 at lib/refcount.c:28 refcount_warn_saturate+0x118/0x180
[    0.717661] Modules linked in:
[    0.717816] CPU: 2 UID: 1000 PID: 138 Comm: poc9 Not tainted 6.18.13 #3 PREEMPT(full) 
[    0.718138] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[    0.718591] RIP: 0010:refcount_warn_saturate+0x118/0x180
[    0.718805] Code: 0f b6 05 aa bf 05 02 3c 01 0f 87 d7 db 5d ff a8 01 0f 85 39 ff ff ff 48 c7 c7 78 71 ec 82 c6 05 8c bf 05 02 01 e8 78 f0 78 ff <0f> 0b c9 31 c0 31 f6 31 ff e9 55 4c 45 ff 0f b6 05 73 bf 05 02 3c
[    0.719521] RSP: 0018:ffffc9000048b790 EFLAGS: 00010246
[    0.719722] RAX: 0000000000000000 RBX: ffff888006c74200 RCX: 0000000000000000
[    0.719985] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[poc9-vdpa] port[    0.720257] RBP: ffffc9000048b798 R08: 0000000000000000 R09: 0000000000000000
id=135 rcvbuf=23[    0.720580] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880075ea000
04 soerr=105 dro[    0.720869] R13: ffff888006c74200 R14: 00000000fffffff5 R15: ffffc9000048b920
ps=0 get 2/0 sen[    0.721165] FS:  000076880ed826c0(0000) GS:ffff88809a460000(0000) knlGS:0000000000000000
d_eagain=0
[    0.721534] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.721768] CR2: 000076880ed801c8 CR3: 0000000008a61000 CR4: 0000000000450ef0
[    0.722055] PKRU: 55555554
[    0.722159] Call Trace:
[    0.722253]  <TASK>
[    0.722339]  sk_skb_reason_drop+0x203/0x210
[    0.722512]  ? up_read+0x22/0x30
[    0.722638]  vdpa_nl_cmd_dev_config_get_doit+0xc7/0x1d0
[    0.722832]  genl_family_rcv_msg_doit+0xcf/0x120
[    0.723018]  genl_rcv_msg+0x161/0x290
[    0.723157]  ? __pfx_vdpa_nl_cmd_dev_config_get_doit+0x10/0x10
[    0.723381]  ? __pfx_genl_rcv_msg+0x10/0x10
[    0.727944]  netlink_rcv_skb+0x41/0xf0
[    0.728136]  genl_rcv+0x28/0x50
[    0.728281]  netlink_unicast+0x1d8/0x2b0
[    0.728483]  netlink_sendmsg+0x212/0x440
[    0.728673]  __sys_sendto+0x1f3/0x200
[    0.728859]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.729076]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.729287]  ? __lock_acquire+0x831/0x2980
[    0.729491]  __x64_sys_sendto+0x24/0x40
[    0.729665]  x64_sys_call+0x1d15/0x2350
[    0.729838]  do_syscall_64+0x90/0xc60
[    0.730010]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.730226]  ? lock_acquire+0xcc/0x2e0
[    0.730391]  ? __folio_batch_add_and_move+0x24b/0x370
[    0.730623]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.730835]  ? find_held_lock+0x31/0x90
[    0.731010]  ? __folio_batch_add_and_move+0x1ab/0x370
[    0.731238]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.731465]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.731677]  ? find_held_lock+0x31/0x90
[    0.731851]  ? rcu_read_unlock+0x1f/0x80
[    0.732029]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.732247]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.732474]  ? rcu_read_unlock+0x29/0x80
[    0.732652]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.732864]  ? do_anonymous_page+0x101/0x840
[    0.733055]  ? ___pte_offset_map+0x1d2/0x290
[    0.733255]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.733482]  ? __handle_mm_fault+0xa8e/0xf40
[    0.733693]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.733904]  ? find_held_lock+0x31/0x90
[    0.734079]  ? exc_page_fault+0x98/0x2c0
[    0.734257]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.734490]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.734709]  ? do_user_addr_fault+0x37b/0x6e0
[    0.734905]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.735118]  ? irqentry_exit_to_user_mode+0xf4/0x300
[    0.735340]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.735566]  ? irqentry_exit+0x77/0xb0
[    0.735737]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.735949]  ? exc_page_fault+0xbf/0x2c0
[    0.736124]  ? srso_alias_return_thunk+0x5/0xfbef5
[    0.736340]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[    0.736576] RIP: 0033:0x434e6c
[    0.736720] Code: fa 6e 03 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c3 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 44 24 08 e8 40 6f 03 00 48 8b
[    0.737513] RSP: 002b:000076880ed80190 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
[    0.737841] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000434e6c
[    0.738154] RDX: 0000000000000020 RSI: 000076880ed801d0 RDI: 0000000000000003
[    0.738473] RBP: 0000000069b8ab57 R08: 00000000004b3cf0 R09: 000000000000000c
[    0.738767] R10: 0000000000000000 R11: 0000000000000293 R12: 000000000f71e860
[    0.739075] R13: 0000000000000013 R14: 000076880ed82cdc R15: 00007fff0dab68e7
[    0.739415]  </TASK>
[    0.739526] irq event stamp: 785
[    0.739675] hardirqs last  enabled at (793): [<ffffffff815153f0>] __up_console_sem+0x90/0xa0
[    0.740039] hardirqs last disabled at (800): [<ffffffff815153d5>] __up_console_sem+0x75/0xa0
[    0.740410] softirqs last  enabled at (362): [<ffffffff81449bcd>] __irq_exit_rcu+0x12d/0x150
[    0.740782] softirqs last disabled at (357): [<ffffffff81449bcd>] __irq_exit_rcu+0x12d/0x150
[    0.741145] ---[ end trace 0000000000000000 ]---
[poc9-vdpa] portid=135 rcvbuf=2304 soerr=0 drops=0 get 98859/0 send_eagain=0
[poc9-vdpa] portid=135 rcvbuf=2304 soerr=0 drops=0 get 204383/0 send_eagain=0
[poc9-vdpa] portid=135 rcvbuf=2304 soerr=0 drops=0 get 319574/0 send_eagain=0
[    4.037387] BUG: kernel NULL pointer dereference, address: 0000000000000060
[    4.037612] #PF: supervisor read access in kernel mode
[    4.037761] #PF: error_code(0x0000) - not-present page
[    4.037914] PGD 994c067 P4D 994c067 PUD 994d067 PMD 0 
[    4.038066] Oops: Oops: 0000 [#1] SMP NOPTI
[    4.038191] CPU: 4 UID: 1000 PID: 140 Comm: poc9 Tainted: G        W           6.18.13 #3 PREEMPT(full) 
[    4.038463] Tainted: [W]=WARN
[    4.038557] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[    4.038869] RIP: 0010:sock_wfree+0x1d/0x3f0
[    4.038994] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 83 ec 10 48 8b 5f 18 44 8b 97 d8 00 00 00 <48> 8b 43 60 f6 c4 02 74 51 44 89 d0 44 89 d2 48 8d 8b 94 02 00 00
[    4.039511] RSP: 0018:ffffc9000049b8f0 EFLAGS: 00010286
[    4.039665] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[    4.039874] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801f8aa100
[    4.040076] RBP: ffffc9000049b918 R08: 0000000000000000 R09: 0000000000000000
[    4.040278] R10: 00000000000003c0 R11: 0000000000000000 R12: ffff8880075ea000
[    4.040482] R13: ffff88801f8aa100 R14: 00000000fffffff5 R15: ffffc9000049baf0
[    4.040685] FS:  000076880dd806c0(0000) GS:ffff88809a560000(0000) knlGS:0000000000000000
[    4.040908] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.041071] CR2: 0000000000000060 CR3: 0000000008a61000 CR4: 0000000000450ef0
[    4.041275] PKRU: 55555554
[    4.041356] Call Trace:
[    4.041434]  <TASK>
[    4.041502]  unix_destruct_scm+0x77/0x90
[    4.041620]  skb_release_head_state+0x27/0xb0
[    4.041750]  sk_skb_reason_drop+0x55/0x210
[    4.041868]  ? up_read+0x22/0x30
[    4.041976]  vdpa_nl_cmd_dev_config_get_doit+0xc7/0x1d0
[    4.042140]  genl_family_rcv_msg_doit+0xcf/0x120
[    4.042280]  genl_rcv_msg+0x161/0x290
[    4.042387]  ? __pfx_vdpa_nl_cmd_dev_config_get_doit+0x10/0x10
[    4.042558]  ? __pfx_genl_rcv_msg+0x10/0x10
[    4.042679]  netlink_rcv_skb+0x41/0xf0
[    4.042798]  genl_rcv+0x28/0x50
[    4.042892]  netlink_unicast+0x1d8/0x2b0
[    4.043009]  netlink_sendmsg+0x212/0x440
[    4.043127]  __sys_sendto+0x1f3/0x200
[    4.043238]  ? __sys_sendto+0x1aa/0x200
[    4.043351]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.043493]  ? x64_sys_call+0x1d15/0x2350
[    4.043610]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.043747]  ? do_syscall_64+0x1b5/0xc60
[    4.043867]  __x64_sys_sendto+0x24/0x40
[    4.043979]  x64_sys_call+0x1d15/0x2350
[    4.044091]  do_syscall_64+0x90/0xc60
[    4.044200]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.044337]  ? x64_sys_call+0x1d15/0x2350
[    4.044456]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.044597]  ? do_syscall_64+0x1b5/0xc60
[    4.044712]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.044851]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.044990]  ? x64_sys_call+0x1d15/0x2350
[    4.045106]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.045243]  ? do_syscall_64+0x1b5/0xc60
[    4.045358]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.045498]  ? x64_sys_call+0x1d15/0x2350
[    4.045614]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.045750]  ? do_syscall_64+0x1b5/0xc60
[    4.045863]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.046007]  ? do_syscall_64+0x1b5/0xc60
[    4.046121]  ? srso_alias_return_thunk+0x5/0xfbef5
[    4.046259]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[    4.046407] RIP: 0033:0x434e6c
[    4.046500] Code: fa 6e 03 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c3 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 44 24 08 e8 40 6f 03 00 48 8b
[    4.047008] RSP: 002b:000076880dd7e190 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
[    4.047218] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000434e6c
[    4.047420] RDX: 0000000000000020 RSI: 000076880dd7e1d0 RDI: 0000000000000003
[    4.047618] RBP: 0000000069b93bd6 R08: 00000000004b3cf0 R09: 000000000000000c
[    4.047816] R10: 0000000000000000 R11: 0000000000000293 R12: 000000000f71e860
[    4.048023] R13: 0000000000000013 R14: 000076880dd80cdc R15: 00007fff0dab68e7
[    4.048228]  </TASK>
[    4.048295] Modules linked in:
[    4.048387] CR2: 0000000000000060
[    4.048494] ---[ end trace 0000000000000000 ]---
[    4.059378] RIP: 0010:sock_wfree+0x1d/0x3f0
[    4.059511] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 83 ec 10 48 8b 5f 18 44 8b 97 d8 00 00 00 <48> 8b 43 60 f6 c4 02 74 51 44 89 d0 44 89 d2 48 8d 8b 94 02 00 00
[    4.060019] RSP: 0018:ffffc9000049b8f0 EFLAGS: 00010286
[    4.060168] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[    4.060367] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801f8aa100
[    4.060574] RBP: ffffc9000049b918 R08: 0000000000000000 R09: 0000000000000000
[    4.060776] R10: 00000000000003c0 R11: 0000000000000000 R12: ffff8880075ea000
[    4.060978] R13: ffff88801f8aa100 R14: 00000000fffffff5 R15: ffffc9000049baf0
[    4.061183] FS:  000076880dd806c0(0000) GS:ffff88809a560000(0000) knlGS:0000000000000000
[    4.061416] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.061579] CR2: 0000000000000060 CR3: 0000000008a61000 CR4: 0000000000450ef0
[    4.061782] PKRU: 55555554
[    4.061863] Kernel panic - not syncing: Fatal exception
[    4.062096] Kernel Offset: disabled
[    4.062204] Rebooting in 1 seconds..


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] vdpa: don't free reply skb after genlmsg_reply()
  2026-03-17  1:22 ` Paul Moses
@ 2026-03-20 21:11   ` Paul Moses
  2026-03-20 22:37     ` Michael S. Tsirkin
  0 siblings, 1 reply; 4+ messages in thread
From: Paul Moses @ 2026-03-20 21:11 UTC (permalink / raw)
  To: Michael S . Tsirkin, Jason Wang, Xuan Zhuo, Eugenio Pérez,
	Eli Cohen, Parav Pandit
  Cc: virtualization, linux-kernel, Paul Moses, stable

FYI, I'm finished with this:

preconditions:
- local unprivileged user
- initial network namespace only
- existing vdpa device

impact:
- DoS only
- immediate netlink_ack() deref of the request skb makes controlled corruption practically unworkable

Feel free to modify patch and only give me "reported by". 

Thanks,
Paul



On Monday, March 16th, 2026 at 8:22 PM, Paul Moses <p@1g4.org> wrote:

> Now that I've wrapped up elsewhere, I can focus on this. Let me
> know if there's any questions.
> 
> Thanks,
> Paul
> 
> [    0.716942] ------------[ cut here ]------------
> [    0.717160] refcount_t: underflow; use-after-free.
> [    0.717356] WARNING: CPU: 2 PID: 138 at lib/refcount.c:28 refcount_warn_saturate+0x118/0x180
> [    0.717661] Modules linked in:
> [    0.717816] CPU: 2 UID: 1000 PID: 138 Comm: poc9 Not tainted 6.18.13 #3 PREEMPT(full)
> [    0.718138] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
> [    0.718591] RIP: 0010:refcount_warn_saturate+0x118/0x180
> [    0.718805] Code: 0f b6 05 aa bf 05 02 3c 01 0f 87 d7 db 5d ff a8 01 0f 85 39 ff ff ff 48 c7 c7 78 71 ec 82 c6 05 8c bf 05 02 01 e8 78 f0 78 ff <0f> 0b c9 31 c0 31 f6 31 ff e9 55 4c 45 ff 0f b6 05 73 bf 05 02 3c
> [    0.719521] RSP: 0018:ffffc9000048b790 EFLAGS: 00010246
> [    0.719722] RAX: 0000000000000000 RBX: ffff888006c74200 RCX: 0000000000000000
> [    0.719985] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> [poc9-vdpa] port[    0.720257] RBP: ffffc9000048b798 R08: 0000000000000000 R09: 0000000000000000
> id=135 rcvbuf=23[    0.720580] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880075ea000
> 04 soerr=105 dro[    0.720869] R13: ffff888006c74200 R14: 00000000fffffff5 R15: ffffc9000048b920
> ps=0 get 2/0 sen[    0.721165] FS:  000076880ed826c0(0000) GS:ffff88809a460000(0000) knlGS:0000000000000000
> d_eagain=0
> [    0.721534] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [    0.721768] CR2: 000076880ed801c8 CR3: 0000000008a61000 CR4: 0000000000450ef0
> [    0.722055] PKRU: 55555554
> [    0.722159] Call Trace:
> [    0.722253]  <TASK>
> [    0.722339]  sk_skb_reason_drop+0x203/0x210
> [    0.722512]  ? up_read+0x22/0x30
> [    0.722638]  vdpa_nl_cmd_dev_config_get_doit+0xc7/0x1d0
> [    0.722832]  genl_family_rcv_msg_doit+0xcf/0x120
> [    0.723018]  genl_rcv_msg+0x161/0x290
> [    0.723157]  ? __pfx_vdpa_nl_cmd_dev_config_get_doit+0x10/0x10
> [    0.723381]  ? __pfx_genl_rcv_msg+0x10/0x10
> [    0.727944]  netlink_rcv_skb+0x41/0xf0
> [    0.728136]  genl_rcv+0x28/0x50
> [    0.728281]  netlink_unicast+0x1d8/0x2b0
> [    0.728483]  netlink_sendmsg+0x212/0x440
> [    0.728673]  __sys_sendto+0x1f3/0x200
> [    0.728859]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.729076]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.729287]  ? __lock_acquire+0x831/0x2980
> [    0.729491]  __x64_sys_sendto+0x24/0x40
> [    0.729665]  x64_sys_call+0x1d15/0x2350
> [    0.729838]  do_syscall_64+0x90/0xc60
> [    0.730010]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.730226]  ? lock_acquire+0xcc/0x2e0
> [    0.730391]  ? __folio_batch_add_and_move+0x24b/0x370
> [    0.730623]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.730835]  ? find_held_lock+0x31/0x90
> [    0.731010]  ? __folio_batch_add_and_move+0x1ab/0x370
> [    0.731238]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.731465]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.731677]  ? find_held_lock+0x31/0x90
> [    0.731851]  ? rcu_read_unlock+0x1f/0x80
> [    0.732029]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.732247]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.732474]  ? rcu_read_unlock+0x29/0x80
> [    0.732652]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.732864]  ? do_anonymous_page+0x101/0x840
> [    0.733055]  ? ___pte_offset_map+0x1d2/0x290
> [    0.733255]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.733482]  ? __handle_mm_fault+0xa8e/0xf40
> [    0.733693]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.733904]  ? find_held_lock+0x31/0x90
> [    0.734079]  ? exc_page_fault+0x98/0x2c0
> [    0.734257]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.734490]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.734709]  ? do_user_addr_fault+0x37b/0x6e0
> [    0.734905]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.735118]  ? irqentry_exit_to_user_mode+0xf4/0x300
> [    0.735340]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.735566]  ? irqentry_exit+0x77/0xb0
> [    0.735737]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.735949]  ? exc_page_fault+0xbf/0x2c0
> [    0.736124]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    0.736340]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
> [    0.736576] RIP: 0033:0x434e6c
> [    0.736720] Code: fa 6e 03 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c3 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 44 24 08 e8 40 6f 03 00 48 8b
> [    0.737513] RSP: 002b:000076880ed80190 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
> [    0.737841] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000434e6c
> [    0.738154] RDX: 0000000000000020 RSI: 000076880ed801d0 RDI: 0000000000000003
> [    0.738473] RBP: 0000000069b8ab57 R08: 00000000004b3cf0 R09: 000000000000000c
> [    0.738767] R10: 0000000000000000 R11: 0000000000000293 R12: 000000000f71e860
> [    0.739075] R13: 0000000000000013 R14: 000076880ed82cdc R15: 00007fff0dab68e7
> [    0.739415]  </TASK>
> [    0.739526] irq event stamp: 785
> [    0.739675] hardirqs last  enabled at (793): [<ffffffff815153f0>] __up_console_sem+0x90/0xa0
> [    0.740039] hardirqs last disabled at (800): [<ffffffff815153d5>] __up_console_sem+0x75/0xa0
> [    0.740410] softirqs last  enabled at (362): [<ffffffff81449bcd>] __irq_exit_rcu+0x12d/0x150
> [    0.740782] softirqs last disabled at (357): [<ffffffff81449bcd>] __irq_exit_rcu+0x12d/0x150
> [    0.741145] ---[ end trace 0000000000000000 ]---
> [poc9-vdpa] portid=135 rcvbuf=2304 soerr=0 drops=0 get 98859/0 send_eagain=0
> [poc9-vdpa] portid=135 rcvbuf=2304 soerr=0 drops=0 get 204383/0 send_eagain=0
> [poc9-vdpa] portid=135 rcvbuf=2304 soerr=0 drops=0 get 319574/0 send_eagain=0
> [    4.037387] BUG: kernel NULL pointer dereference, address: 0000000000000060
> [    4.037612] #PF: supervisor read access in kernel mode
> [    4.037761] #PF: error_code(0x0000) - not-present page
> [    4.037914] PGD 994c067 P4D 994c067 PUD 994d067 PMD 0
> [    4.038066] Oops: Oops: 0000 [#1] SMP NOPTI
> [    4.038191] CPU: 4 UID: 1000 PID: 140 Comm: poc9 Tainted: G        W           6.18.13 #3 PREEMPT(full)
> [    4.038463] Tainted: [W]=WARN
> [    4.038557] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
> [    4.038869] RIP: 0010:sock_wfree+0x1d/0x3f0
> [    4.038994] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 83 ec 10 48 8b 5f 18 44 8b 97 d8 00 00 00 <48> 8b 43 60 f6 c4 02 74 51 44 89 d0 44 89 d2 48 8d 8b 94 02 00 00
> [    4.039511] RSP: 0018:ffffc9000049b8f0 EFLAGS: 00010286
> [    4.039665] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> [    4.039874] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801f8aa100
> [    4.040076] RBP: ffffc9000049b918 R08: 0000000000000000 R09: 0000000000000000
> [    4.040278] R10: 00000000000003c0 R11: 0000000000000000 R12: ffff8880075ea000
> [    4.040482] R13: ffff88801f8aa100 R14: 00000000fffffff5 R15: ffffc9000049baf0
> [    4.040685] FS:  000076880dd806c0(0000) GS:ffff88809a560000(0000) knlGS:0000000000000000
> [    4.040908] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [    4.041071] CR2: 0000000000000060 CR3: 0000000008a61000 CR4: 0000000000450ef0
> [    4.041275] PKRU: 55555554
> [    4.041356] Call Trace:
> [    4.041434]  <TASK>
> [    4.041502]  unix_destruct_scm+0x77/0x90
> [    4.041620]  skb_release_head_state+0x27/0xb0
> [    4.041750]  sk_skb_reason_drop+0x55/0x210
> [    4.041868]  ? up_read+0x22/0x30
> [    4.041976]  vdpa_nl_cmd_dev_config_get_doit+0xc7/0x1d0
> [    4.042140]  genl_family_rcv_msg_doit+0xcf/0x120
> [    4.042280]  genl_rcv_msg+0x161/0x290
> [    4.042387]  ? __pfx_vdpa_nl_cmd_dev_config_get_doit+0x10/0x10
> [    4.042558]  ? __pfx_genl_rcv_msg+0x10/0x10
> [    4.042679]  netlink_rcv_skb+0x41/0xf0
> [    4.042798]  genl_rcv+0x28/0x50
> [    4.042892]  netlink_unicast+0x1d8/0x2b0
> [    4.043009]  netlink_sendmsg+0x212/0x440
> [    4.043127]  __sys_sendto+0x1f3/0x200
> [    4.043238]  ? __sys_sendto+0x1aa/0x200
> [    4.043351]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.043493]  ? x64_sys_call+0x1d15/0x2350
> [    4.043610]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.043747]  ? do_syscall_64+0x1b5/0xc60
> [    4.043867]  __x64_sys_sendto+0x24/0x40
> [    4.043979]  x64_sys_call+0x1d15/0x2350
> [    4.044091]  do_syscall_64+0x90/0xc60
> [    4.044200]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.044337]  ? x64_sys_call+0x1d15/0x2350
> [    4.044456]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.044597]  ? do_syscall_64+0x1b5/0xc60
> [    4.044712]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.044851]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.044990]  ? x64_sys_call+0x1d15/0x2350
> [    4.045106]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.045243]  ? do_syscall_64+0x1b5/0xc60
> [    4.045358]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.045498]  ? x64_sys_call+0x1d15/0x2350
> [    4.045614]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.045750]  ? do_syscall_64+0x1b5/0xc60
> [    4.045863]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.046007]  ? do_syscall_64+0x1b5/0xc60
> [    4.046121]  ? srso_alias_return_thunk+0x5/0xfbef5
> [    4.046259]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
> [    4.046407] RIP: 0033:0x434e6c
> [    4.046500] Code: fa 6e 03 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c3 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 44 24 08 e8 40 6f 03 00 48 8b
> [    4.047008] RSP: 002b:000076880dd7e190 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
> [    4.047218] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000434e6c
> [    4.047420] RDX: 0000000000000020 RSI: 000076880dd7e1d0 RDI: 0000000000000003
> [    4.047618] RBP: 0000000069b93bd6 R08: 00000000004b3cf0 R09: 000000000000000c
> [    4.047816] R10: 0000000000000000 R11: 0000000000000293 R12: 000000000f71e860
> [    4.048023] R13: 0000000000000013 R14: 000076880dd80cdc R15: 00007fff0dab68e7
> [    4.048228]  </TASK>
> [    4.048295] Modules linked in:
> [    4.048387] CR2: 0000000000000060
> [    4.048494] ---[ end trace 0000000000000000 ]---
> [    4.059378] RIP: 0010:sock_wfree+0x1d/0x3f0
> [    4.059511] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 83 ec 10 48 8b 5f 18 44 8b 97 d8 00 00 00 <48> 8b 43 60 f6 c4 02 74 51 44 89 d0 44 89 d2 48 8d 8b 94 02 00 00
> [    4.060019] RSP: 0018:ffffc9000049b8f0 EFLAGS: 00010286
> [    4.060168] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> [    4.060367] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801f8aa100
> [    4.060574] RBP: ffffc9000049b918 R08: 0000000000000000 R09: 0000000000000000
> [    4.060776] R10: 00000000000003c0 R11: 0000000000000000 R12: ffff8880075ea000
> [    4.060978] R13: ffff88801f8aa100 R14: 00000000fffffff5 R15: ffffc9000049baf0
> [    4.061183] FS:  000076880dd806c0(0000) GS:ffff88809a560000(0000) knlGS:0000000000000000
> [    4.061416] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [    4.061579] CR2: 0000000000000060 CR3: 0000000008a61000 CR4: 0000000000450ef0
> [    4.061782] PKRU: 55555554
> [    4.061863] Kernel panic - not syncing: Fatal exception
> [    4.062096] Kernel Offset: disabled
> [    4.062204] Rebooting in 1 seconds..
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] vdpa: don't free reply skb after genlmsg_reply()
  2026-03-20 21:11   ` Paul Moses
@ 2026-03-20 22:37     ` Michael S. Tsirkin
  0 siblings, 0 replies; 4+ messages in thread
From: Michael S. Tsirkin @ 2026-03-20 22:37 UTC (permalink / raw)
  To: Paul Moses
  Cc: Jason Wang, Xuan Zhuo, Eugenio Pérez, Eli Cohen,
	Parav Pandit, virtualization, linux-kernel, stable

On Fri, Mar 20, 2026 at 09:11:18PM +0000, Paul Moses wrote:
> FYI, I'm finished with this:
> 
> preconditions:
> - local unprivileged user
> - initial network namespace only
> - existing vdpa device
> 
> impact:
> - DoS only
> - immediate netlink_ack() deref of the request skb makes controlled corruption practically unworkable
> 
> Feel free to modify patch and only give me "reported by". 
> 
> Thanks,
> Paul
> 

As I said I will apply yours and a simplification on top.

> 
> On Monday, March 16th, 2026 at 8:22 PM, Paul Moses <p@1g4.org> wrote:
> 
> > Now that I've wrapped up elsewhere, I can focus on this. Let me
> > know if there's any questions.
> > 
> > Thanks,
> > Paul
> > 
> > [    0.716942] ------------[ cut here ]------------
> > [    0.717160] refcount_t: underflow; use-after-free.
> > [    0.717356] WARNING: CPU: 2 PID: 138 at lib/refcount.c:28 refcount_warn_saturate+0x118/0x180
> > [    0.717661] Modules linked in:
> > [    0.717816] CPU: 2 UID: 1000 PID: 138 Comm: poc9 Not tainted 6.18.13 #3 PREEMPT(full)
> > [    0.718138] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
> > [    0.718591] RIP: 0010:refcount_warn_saturate+0x118/0x180
> > [    0.718805] Code: 0f b6 05 aa bf 05 02 3c 01 0f 87 d7 db 5d ff a8 01 0f 85 39 ff ff ff 48 c7 c7 78 71 ec 82 c6 05 8c bf 05 02 01 e8 78 f0 78 ff <0f> 0b c9 31 c0 31 f6 31 ff e9 55 4c 45 ff 0f b6 05 73 bf 05 02 3c
> > [    0.719521] RSP: 0018:ffffc9000048b790 EFLAGS: 00010246
> > [    0.719722] RAX: 0000000000000000 RBX: ffff888006c74200 RCX: 0000000000000000
> > [    0.719985] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> > [poc9-vdpa] port[    0.720257] RBP: ffffc9000048b798 R08: 0000000000000000 R09: 0000000000000000
> > id=135 rcvbuf=23[    0.720580] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880075ea000
> > 04 soerr=105 dro[    0.720869] R13: ffff888006c74200 R14: 00000000fffffff5 R15: ffffc9000048b920
> > ps=0 get 2/0 sen[    0.721165] FS:  000076880ed826c0(0000) GS:ffff88809a460000(0000) knlGS:0000000000000000
> > d_eagain=0
> > [    0.721534] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [    0.721768] CR2: 000076880ed801c8 CR3: 0000000008a61000 CR4: 0000000000450ef0
> > [    0.722055] PKRU: 55555554
> > [    0.722159] Call Trace:
> > [    0.722253]  <TASK>
> > [    0.722339]  sk_skb_reason_drop+0x203/0x210
> > [    0.722512]  ? up_read+0x22/0x30
> > [    0.722638]  vdpa_nl_cmd_dev_config_get_doit+0xc7/0x1d0
> > [    0.722832]  genl_family_rcv_msg_doit+0xcf/0x120
> > [    0.723018]  genl_rcv_msg+0x161/0x290
> > [    0.723157]  ? __pfx_vdpa_nl_cmd_dev_config_get_doit+0x10/0x10
> > [    0.723381]  ? __pfx_genl_rcv_msg+0x10/0x10
> > [    0.727944]  netlink_rcv_skb+0x41/0xf0
> > [    0.728136]  genl_rcv+0x28/0x50
> > [    0.728281]  netlink_unicast+0x1d8/0x2b0
> > [    0.728483]  netlink_sendmsg+0x212/0x440
> > [    0.728673]  __sys_sendto+0x1f3/0x200
> > [    0.728859]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.729076]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.729287]  ? __lock_acquire+0x831/0x2980
> > [    0.729491]  __x64_sys_sendto+0x24/0x40
> > [    0.729665]  x64_sys_call+0x1d15/0x2350
> > [    0.729838]  do_syscall_64+0x90/0xc60
> > [    0.730010]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.730226]  ? lock_acquire+0xcc/0x2e0
> > [    0.730391]  ? __folio_batch_add_and_move+0x24b/0x370
> > [    0.730623]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.730835]  ? find_held_lock+0x31/0x90
> > [    0.731010]  ? __folio_batch_add_and_move+0x1ab/0x370
> > [    0.731238]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.731465]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.731677]  ? find_held_lock+0x31/0x90
> > [    0.731851]  ? rcu_read_unlock+0x1f/0x80
> > [    0.732029]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.732247]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.732474]  ? rcu_read_unlock+0x29/0x80
> > [    0.732652]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.732864]  ? do_anonymous_page+0x101/0x840
> > [    0.733055]  ? ___pte_offset_map+0x1d2/0x290
> > [    0.733255]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.733482]  ? __handle_mm_fault+0xa8e/0xf40
> > [    0.733693]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.733904]  ? find_held_lock+0x31/0x90
> > [    0.734079]  ? exc_page_fault+0x98/0x2c0
> > [    0.734257]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.734490]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.734709]  ? do_user_addr_fault+0x37b/0x6e0
> > [    0.734905]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.735118]  ? irqentry_exit_to_user_mode+0xf4/0x300
> > [    0.735340]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.735566]  ? irqentry_exit+0x77/0xb0
> > [    0.735737]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.735949]  ? exc_page_fault+0xbf/0x2c0
> > [    0.736124]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    0.736340]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
> > [    0.736576] RIP: 0033:0x434e6c
> > [    0.736720] Code: fa 6e 03 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c3 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 44 24 08 e8 40 6f 03 00 48 8b
> > [    0.737513] RSP: 002b:000076880ed80190 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
> > [    0.737841] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000434e6c
> > [    0.738154] RDX: 0000000000000020 RSI: 000076880ed801d0 RDI: 0000000000000003
> > [    0.738473] RBP: 0000000069b8ab57 R08: 00000000004b3cf0 R09: 000000000000000c
> > [    0.738767] R10: 0000000000000000 R11: 0000000000000293 R12: 000000000f71e860
> > [    0.739075] R13: 0000000000000013 R14: 000076880ed82cdc R15: 00007fff0dab68e7
> > [    0.739415]  </TASK>
> > [    0.739526] irq event stamp: 785
> > [    0.739675] hardirqs last  enabled at (793): [<ffffffff815153f0>] __up_console_sem+0x90/0xa0
> > [    0.740039] hardirqs last disabled at (800): [<ffffffff815153d5>] __up_console_sem+0x75/0xa0
> > [    0.740410] softirqs last  enabled at (362): [<ffffffff81449bcd>] __irq_exit_rcu+0x12d/0x150
> > [    0.740782] softirqs last disabled at (357): [<ffffffff81449bcd>] __irq_exit_rcu+0x12d/0x150
> > [    0.741145] ---[ end trace 0000000000000000 ]---
> > [poc9-vdpa] portid=135 rcvbuf=2304 soerr=0 drops=0 get 98859/0 send_eagain=0
> > [poc9-vdpa] portid=135 rcvbuf=2304 soerr=0 drops=0 get 204383/0 send_eagain=0
> > [poc9-vdpa] portid=135 rcvbuf=2304 soerr=0 drops=0 get 319574/0 send_eagain=0
> > [    4.037387] BUG: kernel NULL pointer dereference, address: 0000000000000060
> > [    4.037612] #PF: supervisor read access in kernel mode
> > [    4.037761] #PF: error_code(0x0000) - not-present page
> > [    4.037914] PGD 994c067 P4D 994c067 PUD 994d067 PMD 0
> > [    4.038066] Oops: Oops: 0000 [#1] SMP NOPTI
> > [    4.038191] CPU: 4 UID: 1000 PID: 140 Comm: poc9 Tainted: G        W           6.18.13 #3 PREEMPT(full)
> > [    4.038463] Tainted: [W]=WARN
> > [    4.038557] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
> > [    4.038869] RIP: 0010:sock_wfree+0x1d/0x3f0
> > [    4.038994] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 83 ec 10 48 8b 5f 18 44 8b 97 d8 00 00 00 <48> 8b 43 60 f6 c4 02 74 51 44 89 d0 44 89 d2 48 8d 8b 94 02 00 00
> > [    4.039511] RSP: 0018:ffffc9000049b8f0 EFLAGS: 00010286
> > [    4.039665] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> > [    4.039874] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801f8aa100
> > [    4.040076] RBP: ffffc9000049b918 R08: 0000000000000000 R09: 0000000000000000
> > [    4.040278] R10: 00000000000003c0 R11: 0000000000000000 R12: ffff8880075ea000
> > [    4.040482] R13: ffff88801f8aa100 R14: 00000000fffffff5 R15: ffffc9000049baf0
> > [    4.040685] FS:  000076880dd806c0(0000) GS:ffff88809a560000(0000) knlGS:0000000000000000
> > [    4.040908] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [    4.041071] CR2: 0000000000000060 CR3: 0000000008a61000 CR4: 0000000000450ef0
> > [    4.041275] PKRU: 55555554
> > [    4.041356] Call Trace:
> > [    4.041434]  <TASK>
> > [    4.041502]  unix_destruct_scm+0x77/0x90
> > [    4.041620]  skb_release_head_state+0x27/0xb0
> > [    4.041750]  sk_skb_reason_drop+0x55/0x210
> > [    4.041868]  ? up_read+0x22/0x30
> > [    4.041976]  vdpa_nl_cmd_dev_config_get_doit+0xc7/0x1d0
> > [    4.042140]  genl_family_rcv_msg_doit+0xcf/0x120
> > [    4.042280]  genl_rcv_msg+0x161/0x290
> > [    4.042387]  ? __pfx_vdpa_nl_cmd_dev_config_get_doit+0x10/0x10
> > [    4.042558]  ? __pfx_genl_rcv_msg+0x10/0x10
> > [    4.042679]  netlink_rcv_skb+0x41/0xf0
> > [    4.042798]  genl_rcv+0x28/0x50
> > [    4.042892]  netlink_unicast+0x1d8/0x2b0
> > [    4.043009]  netlink_sendmsg+0x212/0x440
> > [    4.043127]  __sys_sendto+0x1f3/0x200
> > [    4.043238]  ? __sys_sendto+0x1aa/0x200
> > [    4.043351]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.043493]  ? x64_sys_call+0x1d15/0x2350
> > [    4.043610]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.043747]  ? do_syscall_64+0x1b5/0xc60
> > [    4.043867]  __x64_sys_sendto+0x24/0x40
> > [    4.043979]  x64_sys_call+0x1d15/0x2350
> > [    4.044091]  do_syscall_64+0x90/0xc60
> > [    4.044200]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.044337]  ? x64_sys_call+0x1d15/0x2350
> > [    4.044456]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.044597]  ? do_syscall_64+0x1b5/0xc60
> > [    4.044712]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.044851]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.044990]  ? x64_sys_call+0x1d15/0x2350
> > [    4.045106]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.045243]  ? do_syscall_64+0x1b5/0xc60
> > [    4.045358]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.045498]  ? x64_sys_call+0x1d15/0x2350
> > [    4.045614]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.045750]  ? do_syscall_64+0x1b5/0xc60
> > [    4.045863]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.046007]  ? do_syscall_64+0x1b5/0xc60
> > [    4.046121]  ? srso_alias_return_thunk+0x5/0xfbef5
> > [    4.046259]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
> > [    4.046407] RIP: 0033:0x434e6c
> > [    4.046500] Code: fa 6e 03 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c3 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 44 24 08 e8 40 6f 03 00 48 8b
> > [    4.047008] RSP: 002b:000076880dd7e190 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
> > [    4.047218] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000434e6c
> > [    4.047420] RDX: 0000000000000020 RSI: 000076880dd7e1d0 RDI: 0000000000000003
> > [    4.047618] RBP: 0000000069b93bd6 R08: 00000000004b3cf0 R09: 000000000000000c
> > [    4.047816] R10: 0000000000000000 R11: 0000000000000293 R12: 000000000f71e860
> > [    4.048023] R13: 0000000000000013 R14: 000076880dd80cdc R15: 00007fff0dab68e7
> > [    4.048228]  </TASK>
> > [    4.048295] Modules linked in:
> > [    4.048387] CR2: 0000000000000060
> > [    4.048494] ---[ end trace 0000000000000000 ]---
> > [    4.059378] RIP: 0010:sock_wfree+0x1d/0x3f0
> > [    4.059511] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 83 ec 10 48 8b 5f 18 44 8b 97 d8 00 00 00 <48> 8b 43 60 f6 c4 02 74 51 44 89 d0 44 89 d2 48 8d 8b 94 02 00 00
> > [    4.060019] RSP: 0018:ffffc9000049b8f0 EFLAGS: 00010286
> > [    4.060168] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> > [    4.060367] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801f8aa100
> > [    4.060574] RBP: ffffc9000049b918 R08: 0000000000000000 R09: 0000000000000000
> > [    4.060776] R10: 00000000000003c0 R11: 0000000000000000 R12: ffff8880075ea000
> > [    4.060978] R13: ffff88801f8aa100 R14: 00000000fffffff5 R15: ffffc9000049baf0
> > [    4.061183] FS:  000076880dd806c0(0000) GS:ffff88809a560000(0000) knlGS:0000000000000000
> > [    4.061416] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [    4.061579] CR2: 0000000000000060 CR3: 0000000008a61000 CR4: 0000000000450ef0
> > [    4.061782] PKRU: 55555554
> > [    4.061863] Kernel panic - not syncing: Fatal exception
> > [    4.062096] Kernel Offset: disabled
> > [    4.062204] Rebooting in 1 seconds..
> > 


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2026-03-20 22:37 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2026-03-12 11:04 [PATCH] vdpa: don't free reply skb after genlmsg_reply() Paul Moses
2026-03-17  1:22 ` Paul Moses
2026-03-20 21:11   ` Paul Moses
2026-03-20 22:37     ` Michael S. Tsirkin

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