linux.git/drivers/net/netdevsim/netdev.c, branch v6.18.21 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git netdevsim: drop PSP ext ref on forward failure 2026-03-25T10:10:42+00:00 Wesley Atwell atwellwea@gmail.com 2026-03-17T06:14:31+00:00 63e192b8956a27c23d7dd757305cafcaf70d8ee3 [ Upstream commit 7d9351435ebba08bbb60f42793175c9dc714d2fb ] nsim_do_psp() takes an extra reference to the PSP skb extension so the extension survives __dev_forward_skb(). That forward path scrubs the skb and drops attached skb extensions before nsim_psp_handle_ext() can reattach the PSP metadata. If __dev_forward_skb() fails in nsim_forward_skb(), the function returns before nsim_psp_handle_ext() can attach that extension to the skb, leaving the extra reference leaked. Drop the saved PSP extension reference before returning from the forward-failure path. Guard the put because plain or non-decapsulated traffic can also fail forwarding without ever taking the extra PSP reference. Fixes: f857478d6206 ("netdevsim: a basic test PSP implementation") Signed-off-by: Wesley Atwell <atwellwea@gmail.com> Reviewed-by: Daniel Zahka <daniel.zahka@gmail.com> Link: https://patch.msgid.link/20260317061431.1482716-1-atwellwea@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7d9351435ebba08bbb60f42793175c9dc714d2fb ]

nsim_do_psp() takes an extra reference to the PSP skb extension so the
extension survives __dev_forward_skb(). That forward path scrubs the skb
and drops attached skb extensions before nsim_psp_handle_ext() can
reattach the PSP metadata.

If __dev_forward_skb() fails in nsim_forward_skb(), the function returns
before nsim_psp_handle_ext() can attach that extension to the skb, leaving
the extra reference leaked.

Drop the saved PSP extension reference before returning from the
forward-failure path. Guard the put because plain or non-decapsulated
traffic can also fail forwarding without ever taking the extra PSP
reference.

Fixes: f857478d6206 ("netdevsim: a basic test PSP implementation")
Signed-off-by: Wesley Atwell <atwellwea@gmail.com>
Reviewed-by: Daniel Zahka <daniel.zahka@gmail.com>
Link: https://patch.msgid.link/20260317061431.1482716-1-atwellwea@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netdevsim: set the carrier when the device goes up 2025-10-16T00:43:17+00:00 Breno Leitao leitao@debian.org 2025-10-14T09:17:25+00:00 1a8fed52f7be14e45785e8e54d0d0b50fc17dbd8 Bringing a linked netdevsim device down and then up causes communication failure because both interfaces lack carrier. Basically a ifdown/ifup on the interface make the link broken. Commit 3762ec05a9fbda ("netdevsim: add NAPI support") added supported for NAPI, calling netif_carrier_off() in nsim_stop(). This patch re-enables the carrier symmetrically on nsim_open(), in case the device is linked and the peer is up. Signed-off-by: Breno Leitao <leitao@debian.org> Fixes: 3762ec05a9fbda ("netdevsim: add NAPI support") Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://patch.msgid.link/20251014-netdevsim_fix-v2-1-53b40590dae1@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Bringing a linked netdevsim device down and then up causes communication
failure because both interfaces lack carrier. Basically a ifdown/ifup on
the interface make the link broken.

Commit 3762ec05a9fbda ("netdevsim: add NAPI support") added supported
for NAPI, calling netif_carrier_off() in nsim_stop(). This patch
re-enables the carrier symmetrically on nsim_open(), in case the device
is linked and the peer is up.

Signed-off-by: Breno Leitao <leitao@debian.org>
Fixes: 3762ec05a9fbda ("netdevsim: add NAPI support")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20251014-netdevsim_fix-v2-1-53b40590dae1@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
netdevsim: a basic test PSP implementation 2025-09-30T13:17:21+00:00 Jakub Kicinski kuba@kernel.org 2025-09-27T22:54:13+00:00 f857478d62066ee94831a5e0679fc18c246cd534 Provide a PSP implementation for netdevsim. Use psp_dev_encapsulate() and psp_dev_rcv() to do actual encapsulation and decapsulation on skbs, but perform no encryption or decryption. In order to make encryption with a bad key result in a drop on the peer's rx side, we stash our psd's generation number in the first byte of each key before handing to the peer. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Daniel Zahka <daniel.zahka@gmail.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Link: https://patch.msgid.link/20250927225420.1443468-2-kuba@kernel.org Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
Provide a PSP implementation for netdevsim.

Use psp_dev_encapsulate() and psp_dev_rcv() to do actual encapsulation
and decapsulation on skbs, but perform no encryption or decryption. In
order to make encryption with a bad key result in a drop on the peer's
rx side, we stash our psd's generation number in the first byte of each
key before handing to the peer.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Co-developed-by: Daniel Zahka <daniel.zahka@gmail.com>
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Link: https://patch.msgid.link/20250927225420.1443468-2-kuba@kernel.org
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
netdevsim: Fix wild pointer access in nsim_queue_free(). 2025-08-14T00:26:39+00:00 Kuniyuki Iwashima kuniyu@google.com 2025-08-12T16:21:26+00:00 b2cafefaf0473bafb0c3502a8530167d35e06113 syzbot reported the splat below. [0] When nsim_queue_uninit() is called from nsim_init_netdevsim(), register_netdevice() has not been called, thus dev->dstats has not been allocated. Let's not call dev_dstats_rx_dropped_add() in such a case. [0] BUG: unable to handle page fault for address: ffff88809782c020 PF: supervisor write access in kernel mode PF: error_code(0x0002) - not-present page PGD 1b401067 P4D 1b401067 PUD 0 Oops: Oops: 0002 [#1] SMP KASAN NOPTI CPU: 3 UID: 0 PID: 8476 Comm: syz.1.251 Not tainted 6.16.0-syzkaller-06699-ge8d780dcd957 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:local_add arch/x86/include/asm/local.h:33 [inline] RIP: 0010:u64_stats_add include/linux/u64_stats_sync.h:89 [inline] RIP: 0010:dev_dstats_rx_dropped_add include/linux/netdevice.h:3027 [inline] RIP: 0010:nsim_queue_free+0xba/0x120 drivers/net/netdevsim/netdev.c:714 Code: 07 77 6c 4a 8d 3c ed 20 7e f1 8d 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 46 4a 03 1c ed 20 7e f1 8d <4c> 01 63 20 be 00 02 00 00 48 8d 3d 00 00 00 00 e8 61 2f 58 fa 48 RSP: 0018:ffffc900044af150 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: ffff88809782c000 RCX: 00000000000079c3 RDX: 1ffffffff1be2fc7 RSI: ffffffff8c15f380 RDI: ffffffff8df17e38 RBP: ffff88805f59d000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000003 R14: ffff88806ceb3d00 R15: ffffed100dfd308e FS: 0000000000000000(0000) GS:ffff88809782c000(0063) knlGS:00000000f505db40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: ffff88809782c020 CR3: 000000006fc6a000 CR4: 0000000000352ef0 Call Trace: <TASK> nsim_queue_uninit drivers/net/netdevsim/netdev.c:993 [inline] nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1049 [inline] nsim_create+0xd0a/0x1260 drivers/net/netdevsim/netdev.c:1101 __nsim_dev_port_add+0x435/0x7d0 drivers/net/netdevsim/dev.c:1438 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1494 [inline] nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline] nsim_dev_reload_up+0x5b8/0x860 drivers/net/netdevsim/dev.c:1003 devlink_reload+0x322/0x7c0 net/devlink/dev.c:474 devlink_nl_reload_doit+0xe31/0x1410 net/devlink/dev.c:584 genl_family_rcv_msg_doit+0x206/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668 __sys_sendmsg+0x16d/0x220 net/socket.c:2700 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf708e579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f505d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000080000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Modules linked in: CR2: ffff88809782c020 Fixes: 2a68a22304f9 ("netdevsim: account dropped packet length in stats on queue free") Reported-by: syzbot+8aa80c6232008f7b957d@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/688bb9ca.a00a0220.26d0e1.0050.GAE@google.com/ Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250812162130.4129322-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
syzbot reported the splat below. [0]

When nsim_queue_uninit() is called from nsim_init_netdevsim(),
register_netdevice() has not been called, thus dev->dstats has
not been allocated.

Let's not call dev_dstats_rx_dropped_add() in such a case.

[0]
BUG: unable to handle page fault for address: ffff88809782c020
 PF: supervisor write access in kernel mode
 PF: error_code(0x0002) - not-present page
PGD 1b401067 P4D 1b401067 PUD 0
Oops: Oops: 0002 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 8476 Comm: syz.1.251 Not tainted 6.16.0-syzkaller-06699-ge8d780dcd957 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:local_add arch/x86/include/asm/local.h:33 [inline]
RIP: 0010:u64_stats_add include/linux/u64_stats_sync.h:89 [inline]
RIP: 0010:dev_dstats_rx_dropped_add include/linux/netdevice.h:3027 [inline]
RIP: 0010:nsim_queue_free+0xba/0x120 drivers/net/netdevsim/netdev.c:714
Code: 07 77 6c 4a 8d 3c ed 20 7e f1 8d 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 46 4a 03 1c ed 20 7e f1 8d <4c> 01 63 20 be 00 02 00 00 48 8d 3d 00 00 00 00 e8 61 2f 58 fa 48
RSP: 0018:ffffc900044af150 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: ffff88809782c000 RCX: 00000000000079c3
RDX: 1ffffffff1be2fc7 RSI: ffffffff8c15f380 RDI: ffffffff8df17e38
RBP: ffff88805f59d000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000003 R14: ffff88806ceb3d00 R15: ffffed100dfd308e
FS:  0000000000000000(0000) GS:ffff88809782c000(0063) knlGS:00000000f505db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffff88809782c020 CR3: 000000006fc6a000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 nsim_queue_uninit drivers/net/netdevsim/netdev.c:993 [inline]
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1049 [inline]
 nsim_create+0xd0a/0x1260 drivers/net/netdevsim/netdev.c:1101
 __nsim_dev_port_add+0x435/0x7d0 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1494 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x5b8/0x860 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x322/0x7c0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xe31/0x1410 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x206/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmsg+0x16d/0x220 net/socket.c:2700
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf708e579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f505d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000080000080
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
CR2: ffff88809782c020

Fixes: 2a68a22304f9 ("netdevsim: account dropped packet length in stats on queue free")
Reported-by: syzbot+8aa80c6232008f7b957d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/688bb9ca.a00a0220.26d0e1.0050.GAE@google.com/
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250812162130.4129322-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
netdevsim: access ->pp through netmem_desc instead of page 2025-07-24T00:46:54+00:00 Byungchul Park byungchul@sk.com 2025-07-21T02:18:27+00:00 6fd824342a57164d97717325763daee1ef01cbcd To eliminate the use of struct page in page pool, the page pool users should use netmem descriptor and APIs instead. Make netdevsim access ->pp through netmem_desc instead of page. Signed-off-by: Byungchul Park <byungchul@sk.com> Link: https://patch.msgid.link/20250721021835.63939-5-byungchul@sk.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
To eliminate the use of struct page in page pool, the page pool users
should use netmem descriptor and APIs instead.

Make netdevsim access ->pp through netmem_desc instead of page.

Signed-off-by: Byungchul Park <byungchul@sk.com>
Link: https://patch.msgid.link/20250721021835.63939-5-byungchul@sk.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: netdevsim: hook in XDP handling 2025-07-23T01:15:53+00:00 Jakub Kicinski kuba@kernel.org 2025-07-19T08:30:55+00:00 be09f0d1acce9ed8d730ae33969da201948608cd Add basic XDP support by hooking in do_xdp_generic(). This should be enough to validate most basic XDP tests. Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com> Link: https://patch.msgid.link/20250719083059.3209169-2-mohsin.bashr@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Add basic XDP support by hooking in do_xdp_generic().
This should be enough to validate most basic XDP tests.

Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
Link: https://patch.msgid.link/20250719083059.3209169-2-mohsin.bashr@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
netdevsim: implement peer queue flow control 2025-07-15T00:36:50+00:00 Breno Leitao leitao@debian.org 2025-07-11T17:06:59+00:00 ff2ac4df58adb6d7721bb0ce6069e1bd0e613126 Add flow control mechanism between paired netdevsim devices to stop the TX queue during high traffic scenarios. When a receive queue becomes congested (approaching NSIM_RING_SIZE limit), the corresponding transmit queue on the peer device is stopped using netif_subqueue_try_stop(). Once the receive queue has sufficient capacity again, the peer's transmit queue is resumed with netif_tx_wake_queue(). Key changes: * Add nsim_stop_peer_tx_queue() to pause peer TX when RX queue is full * Add nsim_start_peer_tx_queue() to resume peer TX when RX queue drains * Implement queue mapping validation to ensure TX/RX queue count match * Wake all queues during device unlinking to prevent stuck queues * Use RCU protection when accessing peer device references * wake the queues when changing the queue numbers * Remove IFF_NO_QUEUE given it will enqueue packets now The flow control only activates when devices have matching TX/RX queue counts to ensure proper queue mapping. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20250711-netdev_flow_control-v3-1-aa1d5a155762@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Add flow control mechanism between paired netdevsim devices to stop the
TX queue during high traffic scenarios. When a receive queue becomes
congested (approaching NSIM_RING_SIZE limit), the corresponding transmit
queue on the peer device is stopped using netif_subqueue_try_stop().

Once the receive queue has sufficient capacity again, the peer's
transmit queue is resumed with netif_tx_wake_queue().

Key changes:
  * Add nsim_stop_peer_tx_queue() to pause peer TX when RX queue is full
  * Add nsim_start_peer_tx_queue() to resume peer TX when RX queue drains
  * Implement queue mapping validation to ensure TX/RX queue count match
  * Wake all queues during device unlinking to prevent stuck queues
  * Use RCU protection when accessing peer device references
  * wake the queues when changing the queue numbers
  * Remove IFF_NO_QUEUE given it will enqueue packets now

The flow control only activates when devices have matching TX/RX queue
counts to ensure proper queue mapping.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250711-netdev_flow_control-v3-1-aa1d5a155762@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: netdevsim: Support setting dev->perm_addr on port creation 2025-07-12T00:00:18+00:00 Toke Høiland-Jørgensen toke@redhat.com 2025-07-10T11:18:33+00:00 54cb59cf81b02de847178c054eed7957170e9386 Network management daemons that match on the device permanent address currently have no virtual interface types to test against. NetworkManager, in particular, has carried an out of tree patch to set the permanent address on netdevsim devices to use in its CI for this purpose. To support this use case, support setting netdev->perm_addr when creating a netdevsim port. Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20250710-netdevsim-perm_addr-v4-1-c9db2fecf3bf@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Network management daemons that match on the device permanent address
currently have no virtual interface types to test against.
NetworkManager, in particular, has carried an out of tree patch to set
the permanent address on netdevsim devices to use in its CI for this
purpose.

To support this use case, support setting netdev->perm_addr when
creating a netdevsim port.

Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250710-netdevsim-perm_addr-v4-1-c9db2fecf3bf@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
netdevsim: fix UaF when counting Tx stats 2025-06-22T17:50:23+00:00 Jakub Kicinski kuba@kernel.org 2025-06-20T17:40:07+00:00 5e95c0a3a55aea490420bd6994805edb050cc86b skb may be freed as soon as we put it on the rx queue. Use the len variable like the code did prior to the conversion. Fixes: f9e2511d80c2 ("netdevsim: migrate to dstats stats collection") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
skb may be freed as soon as we put it on the rx queue.
Use the len variable like the code did prior to the conversion.

Fixes: f9e2511d80c2 ("netdevsim: migrate to dstats stats collection")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
netdevsim: account dropped packet length in stats on queue free 2025-06-19T23:15:34+00:00 Breno Leitao leitao@debian.org 2025-06-18T08:32:45+00:00 2a68a22304f90e5ee960cccd86895a50cf154723 Add a call to dev_dstats_rx_dropped_add() in nsim_queue_free() to account for the number of packets dropped when purging the skb queue. This improves the accuracy of RX drop statistics reported by netdevsim. local_bh_{disable, enable}() protection is used to disable preemption, which is necessary given that dev_dstats_rx_dropped_add() access this_cpu_ptr(). See discussion in [1]. Link: https://lore.kernel.org/all/20250617055934.3fd9d322@kernel.org/ [1] Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20250618-netdevsim_stat-v4-4-19fe0d35e28e@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Add a call to dev_dstats_rx_dropped_add() in nsim_queue_free() to
account for the number of packets dropped when purging the skb queue.
This improves the accuracy of RX drop statistics reported by netdevsim.

local_bh_{disable, enable}() protection is used to disable preemption,
which is necessary given that dev_dstats_rx_dropped_add() access
this_cpu_ptr(). See discussion in [1].

Link: https://lore.kernel.org/all/20250617055934.3fd9d322@kernel.org/ [1]
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250618-netdevsim_stat-v4-4-19fe0d35e28e@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>