kernel/linux.git/drivers/net/netdevsim, branch v6.12.80

netdevsim: fix a race issue related to the operation on bpf_bound_progs list

2026-01-30T09:28:42+00:00

[ Upstream commit b97d5eedf4976cc94321243be83b39efe81a0e15 ] The netdevsim driver lacks a protection mechanism for operations on the bpf_bound_progs list. When the nsim_bpf_create_prog() performs list_add_tail, it is possible that nsim_bpf_destroy_prog() is simultaneously performs list_del. Concurrent operations on the list may lead to list corruption and trigger a kernel crash as follows: [ 417.290971] kernel BUG at lib/list_debug.c:62! [ 417.290983] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 417.290992] CPU: 10 PID: 168 Comm: kworker/10:1 Kdump: loaded Not tainted 6.19.0-rc5 #1 [ 417.291003] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 417.291007] Workqueue: events bpf_prog_free_deferred [ 417.291021] RIP: 0010:__list_del_entry_valid_or_report+0xa7/0xc0 [ 417.291034] Code: a8 ff 0f 0b 48 89 fe 48 89 ca 48 c7 c7 48 a1 eb ae e8 ed fb a8 ff 0f 0b 48 89 fe 48 89 c2 48 c7 c7 80 a1 eb ae e8 d9 fb a8 ff <0f> 0b 48 89 d1 48 c7 c7 d0 a1 eb ae 48 89 f2 48 89 c6 e8 c2 fb a8 [ 417.291040] RSP: 0018:ffffb16a40807df8 EFLAGS: 00010246 [ 417.291046] RAX: 000000000000006d RBX: ffff8e589866f500 RCX: 0000000000000000 [ 417.291051] RDX: 0000000000000000 RSI: ffff8e59f7b23180 RDI: ffff8e59f7b23180 [ 417.291055] RBP: ffffb16a412c9000 R08: 0000000000000000 R09: 0000000000000003 [ 417.291059] R10: ffffb16a40807c80 R11: ffffffffaf9edce8 R12: ffff8e594427ac20 [ 417.291063] R13: ffff8e59f7b44780 R14: ffff8e58800b7a05 R15: 0000000000000000 [ 417.291074] FS: 0000000000000000(0000) GS:ffff8e59f7b00000(0000) knlGS:0000000000000000 [ 417.291079] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 417.291083] CR2: 00007fc4083efe08 CR3: 00000001c3626006 CR4: 0000000000770ee0 [ 417.291088] PKRU: 55555554 [ 417.291091] Call Trace: [ 417.291096] [ 417.291103] nsim_bpf_destroy_prog+0x31/0x80 [netdevsim] [ 417.291154] __bpf_prog_offload_destroy+0x2a/0x80 [ 417.291163] bpf_prog_dev_bound_destroy+0x6f/0xb0 [ 417.291171] bpf_prog_free_deferred+0x18e/0x1a0 [ 417.291178] process_one_work+0x18a/0x3a0 [ 417.291188] worker_thread+0x27b/0x3a0 [ 417.291197] ? __pfx_worker_thread+0x10/0x10 [ 417.291207] kthread+0xe5/0x120 [ 417.291214] ? __pfx_kthread+0x10/0x10 [ 417.291221] ret_from_fork+0x31/0x50 [ 417.291230] ? __pfx_kthread+0x10/0x10 [ 417.291236] ret_from_fork_asm+0x1a/0x30 [ 417.291246] Add a mutex lock, to prevent simultaneous addition and deletion operations on the list. Fixes: 31d3ad832948 ("netdevsim: add bpf offload support") Reported-by: Yinhao Hu Reported-by: Kaiyan Mei Signed-off-by: Yun Lu Link: https://patch.msgid.link/20260116095308.11441-1-luyun_611@163.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: netdevsim: fix inconsistent carrier state after link/unlink

2026-01-17T15:31:24+00:00

[ Upstream commit d83dddffe1904e4a576d11a541878850a8e64cd2 ] This patch fixes the edge case behavior on ifup/ifdown and linking/unlinking two netdevsim interfaces: 1. unlink two interfaces netdevsim1 and netdevsim2 2. ifdown netdevsim1 3. ifup netdevsim1 4. link two interfaces netdevsim1 and netdevsim2 5. (Now two interfaces are linked in terms of netdevsim peer, but carrier state of the two interfaces remains DOWN.) This inconsistent behavior is caused by the current implementation, which only cares about the "link, then ifup" order, not "ifup, then link" order. This patch fixes the inconsistency by calling netif_carrier_on() when two netdevsim interfaces are linked. This patch fixes buggy behavior on NetworkManager-based systems which causes the netdevsim test to fail with the following error: # timeout set to 600 # selftests: drivers/net/netdevsim: peer.sh # 2025/12/25 00:54:03 socat[9115] W address is opened in read-write mode but only supports read-only # 2025/12/25 00:56:17 socat[9115] W connect(7, AF=2 192.168.1.1:1234, 16): Connection timed out # 2025/12/25 00:56:17 socat[9115] E TCP:192.168.1.1:1234: Connection timed out # expected 3 bytes, got 0 # 2025/12/25 00:56:17 socat[9109] W exiting on signal 15 not ok 13 selftests: drivers/net/netdevsim: peer.sh # exit=1 This patch also solves timeout on TCP Fast Open (TFO) test in NetworkManager-based systems because it also depends on netdevsim's carrier consistency. Fixes: 1a8fed52f7be ("netdevsim: set the carrier when the device goes up") Signed-off-by: Yohei Kojima Reviewed-by: Breno Leitao Link: https://patch.msgid.link/602c9e1ba5bb2ee1997bb38b1d866c9c3b807ae9.1767624906.git.yk@y-koj.net Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netdevsim: set the carrier when the device goes up

2025-10-23T14:20:31+00:00

[ Upstream commit 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 Fixes: 3762ec05a9fbda ("netdevsim: add NAPI support") Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20251014-netdevsim_fix-v2-1-53b40590dae1@debian.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netdevsim: Mark NAPI ID on skb in nsim_rcv

2025-06-27T10:11:33+00:00

[ Upstream commit f71c549b26a33fd62f1e9c7deeba738bfc73fbfc ] Previously, nsim_rcv was not marking the NAPI ID on the skb, leading to applications seeing a napi ID of 0 when using SO_INCOMING_NAPI_ID. To add to the userland confusion, netlink appears to correctly report the NAPI IDs for netdevsim queues but the resulting file descriptor from a call to accept() was reporting a NAPI ID of 0. Signed-off-by: Joe Damato Link: https://patch.msgid.link/20250424002746.16891-2-jdamato@fastly.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: drv: netdevsim: don't napi_complete() from netpoll

2025-06-19T13:32:31+00:00

[ Upstream commit 1264971017b4d7141352a7fe29021bdfce5d885d ] netdevsim supports netpoll. Make sure we don't call napi_complete() from it, since it may not be scheduled. Breno reports hitting a warning in napi_complete_done(): WARNING: CPU: 14 PID: 104 at net/core/dev.c:6592 napi_complete_done+0x2cc/0x560 __napi_poll+0x2d8/0x3a0 handle_softirqs+0x1fe/0x710 This is presumably after netpoll stole the SCHED bit prematurely. Reported-by: Breno Leitao Fixes: 3762ec05a9fb ("netdevsim: add NAPI support") Tested-by: Breno Leitao Link: https://patch.msgid.link/20250611174643.2769263-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netdevsim: print human readable IP address

2025-02-21T13:01:45+00:00

commit c71bc6da6198a6d88df86094f1052bb581951d65 upstream. Currently, IPSec addresses are printed in hexadecimal format, which is not user-friendly. e.g. # cat /sys/kernel/debug/netdevsim/netdevsim0/ports/0/ipsec SA count=2 tx=20 sa[0] rx ipaddr=0x00000000 00000000 00000000 0100a8c0 sa[0] spi=0x00000101 proto=0x32 salt=0x0adecc3a crypt=1 sa[0] key=0x3167608a ca4f1397 43565909 941fa627 sa[1] tx ipaddr=0x00000000 00000000 00000000 00000000 sa[1] spi=0x00000100 proto=0x32 salt=0x0adecc3a crypt=1 sa[1] key=0x3167608a ca4f1397 43565909 941fa627 This patch updates the code to print the IPSec address in a human-readable format for easier debug. e.g. # cat /sys/kernel/debug/netdevsim/netdevsim0/ports/0/ipsec SA count=4 tx=40 sa[0] tx ipaddr=0.0.0.0 sa[0] spi=0x00000100 proto=0x32 salt=0x0adecc3a crypt=1 sa[0] key=0x3167608a ca4f1397 43565909 941fa627 sa[1] rx ipaddr=192.168.0.1 sa[1] spi=0x00000101 proto=0x32 salt=0x0adecc3a crypt=1 sa[1] key=0x3167608a ca4f1397 43565909 941fa627 sa[2] tx ipaddr=:: sa[2] spi=0x00000100 proto=0x32 salt=0x0adecc3a crypt=1 sa[2] key=0x3167608a ca4f1397 43565909 941fa627 sa[3] rx ipaddr=2000::1 sa[3] spi=0x00000101 proto=0x32 salt=0x0adecc3a crypt=1 sa[3] key=0x3167608a ca4f1397 43565909 941fa627 Reviewed-by: Simon Horman Signed-off-by: Hangbin Liu Link: https://patch.msgid.link/20241010040027.21440-2-liuhangbin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman Signed-off-by: Harshit Mogalapalli

net: netdevsim: try to close UDP port harness races

2025-02-08T08:58:05+00:00

[ Upstream commit 50bf398e1ceacb9a7f85bd3bdca065ebe5cb6159 ] syzbot discovered that we remove the debugfs files after we free the netdev. Try to clean up the relevant dir while the device is still around. Reported-by: syzbot+2e5de9e3ab986b71d2bf@syzkaller.appspotmail.com Fixes: 424be63ad831 ("netdevsim: add UDP tunnel port offload support") Reviewed-by: Michal Swiatkowski Link: https://patch.msgid.link/20250122224503.762705-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: netdevsim: fix nsim_pp_hold_write()

2024-12-27T13:02:04+00:00

[ Upstream commit b9b8301d369b4c876de5255dbf067b19ba88ac71 ] nsim_pp_hold_write() has two problems: 1) It may return with rtnl held, as found by syzbot. 2) Its return value does not propagate an error if any. Fixes: 1580cbcbfe77 ("net: netdevsim: add some fake page pool use") Reported-by: syzbot Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Link: https://patch.msgid.link/20241216083703.1859921-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netdevsim: prevent bad user input in nsim_dev_health_break_write()

2024-12-27T13:02:02+00:00

[ Upstream commit ee76746387f6233bdfa93d7406990f923641568f ] If either a zero count or a large one is provided, kernel can crash. Fixes: 82c93a87bf8b ("netdevsim: implement couple of testing devlink health reporters") Reported-by: syzbot+ea40e4294e58b0292f74@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/675c6862.050a0220.37aaf.00b1.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Jiri Pirko Reviewed-by: Joe Damato Link: https://patch.msgid.link/20241213172518.2415666-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netdevsim: copy addresses for both in and out paths

2024-12-05T13:01:44+00:00

[ Upstream commit 2cf567f421dbfe7e53b7e5ddee9400da10efb75d ] The current code only copies the address for the in path, leaving the out path address set to 0. This patch corrects the issue by copying the addresses for both the in and out paths. Before this patch: # cat /sys/kernel/debug/netdevsim/netdevsim0/ports/0/ipsec SA count=2 tx=20 sa[0] tx ipaddr=0.0.0.0 sa[0] spi=0x00000100 proto=0x32 salt=0x0adecc3a crypt=1 sa[0] key=0x3167608a ca4f1397 43565909 941fa627 sa[1] rx ipaddr=192.168.0.1 sa[1] spi=0x00000101 proto=0x32 salt=0x0adecc3a crypt=1 sa[1] key=0x3167608a ca4f1397 43565909 941fa627 After this patch: = cat /sys/kernel/debug/netdevsim/netdevsim0/ports/0/ipsec SA count=2 tx=20 sa[0] tx ipaddr=192.168.0.2 sa[0] spi=0x00000100 proto=0x32 salt=0x0adecc3a crypt=1 sa[0] key=0x3167608a ca4f1397 43565909 941fa627 sa[1] rx ipaddr=192.168.0.1 sa[1] spi=0x00000101 proto=0x32 salt=0x0adecc3a crypt=1 sa[1] key=0x3167608a ca4f1397 43565909 941fa627 Fixes: 7699353da875 ("netdevsim: add ipsec offload testing") Reviewed-by: Simon Horman Signed-off-by: Hangbin Liu Link: https://patch.msgid.link/20241010040027.21440-3-liuhangbin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin