CVE-2026-23173: net/mlx5e: TC, delete flows only for existing peers
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: TC, delete flows only for existing peers
When deleting TC steering flows, iterate only over actual devcom peers instead of assuming all possible ports exist. This avoids touching non-existent peers and ensures cleanup is limited to devices the driver is currently connected to.
BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor write access in kernel mode #PF: errorcode(0x0002) - not-present page PGD 133c8a067 P4D 0 Oops: Oops: 0002 [#1] SMP CPU: 19 UID: 0 PID: 2169 Comm: tc Not tainted 6.18.0+ #156 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:mlx5etcdelfdbpeersflow+0xbe/0x200 [mlx5core] Code: 00 00 a8 08 74 a8 49 8b 46 18 f6 c4 02 74 9f 4c 8d bf a0 12 00 00 4c 89 ff e8 0e e7 96 e1 49 8b 44 24 08 49 8b 0c 24 4c 89 ff <48> 89 41 08 48 89 08 49 89 2c 24 49 89 5c 24 08 e8 7d ce 96 e1 49 RSP: 0018:ff11000143867528 EFLAGS: 00010246 RAX: 0000000000000000 RBX: dead000000000122 RCX: 0000000000000000 RDX: ff11000143691580 RSI: ff110001026e5000 RDI: ff11000106f3d2a0 RBP: dead000000000100 R08: 00000000000003fd R09: 0000000000000002 R10: ff11000101c75690 R11: ff1100085faea178 R12: ff11000115f0ae78 R13: 0000000000000000 R14: ff11000115f0a800 R15: ff11000106f3d2a0 FS: 00007f35236bf740(0000) GS:ff110008dc809000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 0000000157a01001 CR4: 0000000000373eb0 Call Trace: <TASK> mlx5etcdelflow+0x46/0x270 [mlx5core] mlx5eflowput+0x25/0x50 [mlx5core] mlx5edeleteflower+0x2a6/0x3e0 [mlx5core] tcsetupcbreoffload+0x20/0x80 flreoffload+0x26f/0x2f0 [clsflower] ? mlx5etcreoffloadflowswork+0xc0/0xc0 [mlx5core] ? mlx5etcreoffloadflowswork+0xc0/0xc0 [mlx5core] tcfblockplaybackoffloads+0x9e/0x1c0 tcfblockunbind+0x7b/0xd0 tcfblocksetup+0x186/0x1d0 tcfblockoffloadcmd.isra.0+0xef/0x130 tcfblockoffloadunbind+0x43/0x70 tcfblockput+0x85/0x160 ingressdestroy+0x32/0x110 [schingress] qdiscdestroy+0x44/0x100 qdiscgraft+0x22b/0x610 tcgetqdisc+0x183/0x4d0 rtnetlinkrcvmsg+0x2d7/0x3d0 ? rtnlcalcit.isra.0+0x100/0x100 netlinkrcvskb+0x53/0x100 netlinkunicast+0x249/0x320 ? allocskb+0x102/0x1f0 netlinksendmsg+0x1e3/0x420 socksendmsg+0x38/0x60 syssendmsg+0x1ef/0x230 ? copymsghdrfromuser+0x6c/0xa0 syssendmsg+0x7f/0xc0 ? sysrecvmsg+0x8a/0xc0 ? syssendto+0x119/0x180 syssendmsg+0x61/0xb0 dosyscall64+0x55/0x640 entrySYSCALL64afterhwframe+0x4b/0x53 RIP: 0033:0x7f35238bb764 Code: 15 b9 86 0c 00 f7 d8 64 89 02 b8 ff ff ff ff eb bf 0f 1f 44 00 00 f3 0f 1e fa 80 3d e5 08 0d 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 20 89 55 RSP: 002b:00007ffed4c35638 EFLAGS: 00000202 ORIGRAX: 000000000000002e RAX: ffffffffffffffda RBX: 000055a2efcc75e0 RCX: 00007f35238bb764 RDX: 0000000000000000 RSI: 00007ffed4c356a0 RDI: 0000000000000003 RBP: 00007ffed4c35710 R08: 0000000000000010 R09: 00007f3523984b20 R10: 0000000000000004 R11: 0000000000000202 R12: 00007ffed4c35790 R13: 000000006947df8f R14: 000055a2efcc75e0 R15: 00007ffed4c35780
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-23173?
CVE-2026-23173 is classified as a medium severity vulnerability within the Linux kernel.
How do I fix CVE-2026-23173?
To remediate CVE-2026-23173, update to the patched version of the Linux kernel that addresses this specific flaw.
Which versions of the Linux kernel are affected by CVE-2026-23173?
CVE-2026-23173 affects specific versions of the Linux kernel prior to the security update that resolves this issue.
What does CVE-2026-23173 involve?
CVE-2026-23173 involves improper handling of TC steering flows in the Linux kernel that could lead to unintended behavior when deleting flows.
Is CVE-2026-23173 a remote or local vulnerability?
CVE-2026-23173 is typically classified as a local vulnerability, as it involves actions performed within the context of the kernel.