kernel/linux.git/include/linux/if_vlan.h, branch v6.12.80

net: vlan: Replace BUG() with WARN_ON_ONCE() in vlan_dev_* stubs

2025-08-20T16:30:37+00:00

[ Upstream commit 60a8b1a5d0824afda869f18dc0ecfe72f8dfda42 ] When CONFIG_VLAN_8021Q=n, a set of stub helpers are used, three of these helpers use BUG() unconditionally. This code should not be reached, as callers of these functions should always check for is_vlan_dev() first, but the usage of BUG() is not recommended, replace it with WARN_ON() instead. Reviewed-by: Alex Lazar Reviewed-by: Dragos Tatulea Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20250616132626.1749331-3-gal@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: vlan: Make is_vlan_dev() a stub when VLAN is not configured

2025-08-20T16:30:37+00:00

[ Upstream commit 2de1ba0887e5d3bf02d7c212f380039b34e10aa3 ] Add a stub implementation of is_vlan_dev() that returns false when VLAN support is not compiled in (CONFIG_VLAN_8021Q=n). This allows us to compile-out VLAN-dependent dead code when it is not needed. This also resolves the following compilation error when: * CONFIG_VLAN_8021Q=n * CONFIG_OBJTOOL=y * CONFIG_OBJTOOL_WERROR=y drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.o: error: objtool: parse_mirred.isra.0+0x370: mlx5e_tc_act_vlan_add_push_action() missing __noreturn in .c/.h or NORETURN() in noreturns.h The error occurs because objtool cannot determine that unreachable BUG() (which doesn't return) calls in VLAN code paths are actually dead code when VLAN support is disabled. Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20250616132626.1749331-2-gal@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

af_packet: fix vlan_get_protocol_dgram() vs MSG_PEEK

2025-01-09T12:33:42+00:00

[ Upstream commit f91a5b8089389eb408501af2762f168c3aaa7b79 ] Blamed commit forgot MSG_PEEK case, allowing a crash [1] as found by syzbot. Rework vlan_get_protocol_dgram() to not touch skb at all, so that it can be used from many cpus on the same skb. Add a const qualifier to skb argument. [1] skbuff: skb_under_panic: text:ffffffff8a8ccd05 len:29 put:14 head:ffff88807fc8e400 data:ffff88807fc8e3f4 tail:0x11 end:0x140 dev: ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:206 ! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 UID: 0 PID: 5892 Comm: syz-executor883 Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:skb_panic net/core/skbuff.c:206 [inline] RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216 Code: 0b 8d 48 c7 c6 86 d5 25 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 5a 69 79 f7 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 RSP: 0018:ffffc900038d7638 EFLAGS: 00010282 RAX: 0000000000000087 RBX: dffffc0000000000 RCX: 609ffd18ea660600 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffff88802483c8d0 R08: ffffffff817f0a8c R09: 1ffff9200071ae60 R10: dffffc0000000000 R11: fffff5200071ae61 R12: 0000000000000140 R13: ffff88807fc8e400 R14: ffff88807fc8e3f4 R15: 0000000000000011 FS: 00007fbac5e006c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbac5e00d58 CR3: 000000001238e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_push+0xe5/0x100 net/core/skbuff.c:2636 vlan_get_protocol_dgram+0x165/0x290 net/packet/af_packet.c:585 packet_recvmsg+0x948/0x1ef0 net/packet/af_packet.c:3552 sock_recvmsg_nosec net/socket.c:1033 [inline] sock_recvmsg+0x22f/0x280 net/socket.c:1055 ____sys_recvmsg+0x1c6/0x480 net/socket.c:2803 ___sys_recvmsg net/socket.c:2845 [inline] do_recvmmsg+0x426/0xab0 net/socket.c:2940 __sys_recvmmsg net/socket.c:3014 [inline] __do_sys_recvmmsg net/socket.c:3037 [inline] __se_sys_recvmmsg net/socket.c:3030 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3030 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 79eecf631c14 ("af_packet: Handle outgoing VLAN packets without hardware offloading") Reported-by: syzbot+74f70bb1cb968bf09e4f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6772c485.050a0220.2f3838.04c5.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Chengen Du Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20241230161004.2681892-2-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: make vlan_get_tag() return -ENODATA instead of -EINVAL

2023-12-14T00:16:41+00:00

__vlan_hwaccel_get_tag() is used in veth XDP hints implementation, its return value (-EINVAL if skb is not VLAN tagged) is passed to bpf code, but XDP hints specification requires drivers to return -ENODATA, if a hint cannot be provided for a particular packet. Solve this inconsistency by changing error return value of __vlan_hwaccel_get_tag() from -EINVAL to -ENODATA, do the same thing to __vlan_get_tag(), because this function is supposed to follow the same convention. This, in turn, makes -ENODATA the only non-zero value vlan_get_tag() can return. We can do this with no side effects, because none of the users of the 3 above-mentioned functions rely on the exact value. Suggested-by: Jesper Dangaard Brouer Acked-by: Stanislav Fomichev Signed-off-by: Larysa Zaremba Link: https://lore.kernel.org/r/20231205210847.28460-14-larysa.zaremba@intel.com Signed-off-by: Alexei Starovoitov

net: vlan: update wrong comments

2023-08-04T10:02:46+00:00

vlan_insert_tag() and friends do not allocate a new skb. However they might allocate a new skb->head. Update their comments to better describe their behavior. Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Signed-off-by: David S. Miller

net: add vlan_get_protocol_and_depth() helper

2023-05-10T09:25:55+00:00

Before blamed commit, pskb_may_pull() was used instead of skb_header_pointer() in __vlan_get_protocol() and friends. Few callers depended on skb->head being populated with MAC header, syzbot caught one of them (skb_mac_gso_segment()) Add vlan_get_protocol_and_depth() to make the intent clearer and use it where sensible. This is a more generic fix than commit e9d3f80935b6 ("net/af_packet: make sure to pull mac header") which was dealing with a similar issue. kernel BUG at include/linux/skbuff.h:2655 ! invalid opcode: 0000 [#1] SMP KASAN CPU: 0 PID: 1441 Comm: syz-executor199 Not tainted 6.1.24-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 RIP: 0010:__skb_pull include/linux/skbuff.h:2655 [inline] RIP: 0010:skb_mac_gso_segment+0x68f/0x6a0 net/core/gro.c:136 Code: fd 48 8b 5c 24 10 44 89 6b 70 48 c7 c7 c0 ae 0d 86 44 89 e6 e8 a1 91 d0 00 48 c7 c7 00 af 0d 86 48 89 de 31 d2 e8 d1 4a e9 ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 RSP: 0018:ffffc90001bd7520 EFLAGS: 00010286 RAX: ffffffff8469736a RBX: ffff88810f31dac0 RCX: ffff888115a18b00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90001bd75e8 R08: ffffffff84697183 R09: fffff5200037adf9 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000012 R13: 000000000000fee5 R14: 0000000000005865 R15: 000000000000fed7 FS: 000055555633f300(0000) GS:ffff8881f6a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000000 CR3: 0000000116fea000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: [] __skb_gso_segment+0x32d/0x4c0 net/core/dev.c:3419 [] skb_gso_segment include/linux/netdevice.h:4819 [inline] [] validate_xmit_skb+0x3aa/0xee0 net/core/dev.c:3725 [] __dev_queue_xmit+0x1332/0x3300 net/core/dev.c:4313 [] dev_queue_xmit+0x17/0x20 include/linux/netdevice.h:3029 [] packet_snd net/packet/af_packet.c:3111 [inline] [] packet_sendmsg+0x49d2/0x6470 net/packet/af_packet.c:3142 [] sock_sendmsg_nosec net/socket.c:716 [inline] [] sock_sendmsg net/socket.c:736 [inline] [] __sys_sendto+0x472/0x5f0 net/socket.c:2139 [] __do_sys_sendto net/socket.c:2151 [inline] [] __se_sys_sendto net/socket.c:2147 [inline] [] __x64_sys_sendto+0xe5/0x100 net/socket.c:2147 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x2f/0x50 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 469aceddfa3e ("vlan: consolidate VLAN parsing code and limit max parsing depth") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: Toke Høiland-Jørgensen Cc: Willem de Bruijn Reviewed-by: Simon Horman Signed-off-by: David S. Miller

net: dsa: tag_ocelot: call only the relevant portion of __skb_vlan_pop() on TX

2023-04-23T13:16:45+00:00

ocelot_xmit_get_vlan_info() calls __skb_vlan_pop() as the most appropriate helper I could find which strips away a VLAN header. That's all I need it to do, but __skb_vlan_pop() has more logic, which will become incompatible with the future revert of commit 6d1ccff62780 ("net: reset mac header in dev_start_xmit()"). Namely, it performs a sanity check on skb_mac_header(), which will stop being set after the above revert, so it will return an error instead of removing the VLAN tag. ocelot_xmit_get_vlan_info() gets called in 2 circumstances: (1) the port is under a VLAN-aware bridge and the bridge sends VLAN-tagged packets (2) the port is under a VLAN-aware bridge and somebody else (an 8021q upper) sends VLAN-tagged packets (using a VID that isn't in the bridge vlan tables) In case (1), there is actually no bug to defend against, because br_dev_xmit() calls skb_reset_mac_header() and things continue to work. However, in case (2), illustrated using the commands below, it can be seen that our intervention is needed, since __skb_vlan_pop() complains: $ ip link add br0 type bridge vlan_filtering 1 && ip link set br0 up $ ip link set $eth master br0 && ip link set $eth up $ ip link add link $eth name $eth.100 type vlan id 100 && ip link set $eth.100 up $ ip addr add 192.168.100.1/24 dev $eth.100 I could fend off the checks in __skb_vlan_pop() with some skb_mac_header_was_set() calls, but seeing how few callers of __skb_vlan_pop() there are from TX paths, that seems rather unproductive. As an alternative solution, extract the bare minimum logic to strip a VLAN header, and move it to a new helper named vlan_remove_tag(), close to the definition of vlan_insert_tag(). Document it appropriately and make ocelot_xmit_get_vlan_info() call this smaller helper instead. Seeing that it doesn't appear illegal to test skb->protocol in the TX path, I guess it would be a good for vlan_remove_tag() to also absorb the vlan_set_encap_proto() function call. Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Reviewed-by: Florian Fainelli Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller

net: vlan: introduce skb_vlan_eth_hdr()

2023-04-23T13:16:44+00:00

Similar to skb_eth_hdr() introduced in commit 96cc4b69581d ("macvlan: do not assume mac_header is set in macvlan_broadcast()"), let's introduce a skb_vlan_eth_hdr() helper which can be used in TX-only code paths to get to the VLAN header based on skb->data rather than based on the skb_mac_header(skb). We also consolidate the drivers that dereference skb->data to go through this helper. Signed-off-by: Vladimir Oltean Reviewed-by: Eric Dumazet Reviewed-by: Simon Horman Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller

net: vlan: don't adjust MAC header in __vlan_insert_inner_tag() unless set

2023-04-23T13:16:44+00:00

This is a preparatory change for the deletion of skb_reset_mac_header(skb) from __dev_queue_xmit(). After that deletion, skb_mac_header(skb) will no longer be set in TX paths, from which __vlan_insert_inner_tag() can still be called (perhaps indirectly). If we don't make this change, then an unset MAC header (equal to ~0U) will become set after the adjustment with VLAN_HLEN. Signed-off-by: Vladimir Oltean Reviewed-by: Eric Dumazet Reviewed-by: Simon Horman Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller

net: remove skb->vlan_present

2022-11-12T02:18:05+00:00

skb->vlan_present seems redundant. We can instead derive it from this boolean expression: vlan_present = skb->vlan_proto != 0 || skb->vlan_tci != 0 Add a new union, to access both fields in a single load/store when possible. union { u32 vlan_all; struct { __be16 vlan_proto; __u16 vlan_tci; }; }; This allows following patch to remove a conditional test in GRO stack. Note: We move remcsum_offload to keep TC_AT_INGRESS_MASK and SKB_MONO_DELIVERY_TIME_MASK unchanged. Signed-off-by: Eric Dumazet Acked-by: Yonghong Song Acked-by: Martin KaFai Lau Signed-off-by: Jakub Kicinski