CVE-2024-40957

seg6: fix parameter passing when calling NF_HOOK() in End.DX4 and End.DX6 behaviors

MEDIUM

5.5

CVSS Score

Published: July 12, 2024 at 12:31 PM UTC

Updated: August 5, 2026 at 12:04 PM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.7%

SSVC

No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: seg6: fix parameter passing when calling NF_HOOK() in End.DX4 and End.DX6 behaviors input_action_end_dx4() and input_action_end_dx6() are called NF_HOOK() for PREROUTING hook, in PREROUTING hook, we should passing a valid indev, and a NULL outdev to NF_HOOK(), otherwise may trigger a NULL pointer dereference, as below: [74830.647293] BUG: kernel NULL pointer dereference, address: 0000000000000090 [74830.655633] #PF: supervisor read access in kernel mode [74830.657888] #PF: error_code(0x0000) - not-present page [74830.659500] PGD 0 P4D 0 [74830.660450] Oops: 0000 [#1] PREEMPT SMP PTI ... [74830.664953] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [74830.666569] RIP: 0010:rpfilter_mt+0x44/0x15e [ipt_rpfilter] ... [74830.689725] Call Trace: [74830.690402] <IRQ> [74830.690953] ? show_trace_log_lvl+0x1c4/0x2df [74830.692020] ? show_trace_log_lvl+0x1c4/0x2df [74830.693095] ? ipt_do_table+0x286/0x710 [ip_tables] [74830.694275] ? __die_body.cold+0x8/0xd [74830.695205] ? page_fault_oops+0xac/0x140 [74830.696244] ? exc_page_fault+0x62/0x150 [74830.697225] ? asm_exc_page_fault+0x22/0x30 [74830.698344] ? rpfilter_mt+0x44/0x15e [ipt_rpfilter] [74830.699540] ipt_do_table+0x286/0x710 [ip_tables] [74830.700758] ? ip6_route_input+0x19d/0x240 [74830.701752] nf_hook_slow+0x3f/0xb0 [74830.702678] input_action_end_dx4+0x19b/0x1e0 [74830.703735] ? input_action_end_t+0xe0/0xe0 [74830.704734] seg6_local_input_core+0x2d/0x60 [74830.705782] lwtunnel_input+0x5b/0xb0 [74830.706690] __netif_receive_skb_one_core+0x63/0xa0 [74830.707825] process_backlog+0x99/0x140 [74830.709538] __napi_poll+0x2c/0x160 [74830.710673] net_rx_action+0x296/0x350 [74830.711860] __do_softirq+0xcb/0x2ac [74830.713049] do_softirq+0x63/0x90 input_action_end_dx4() passing a NULL indev to NF_HOOK(), and finally trigger a NULL dereference in rpfilter_mt()->rpfilter_is_loopback(): static bool rpfilter_is_loopback(const struct sk_buff *skb, const struct net_device *in) { // in is NULL return skb->pkt_type == PACKET_LOOPBACK || in->flags & IFF_LOOPBACK; }

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

5.15 ≤ v < 5.15.1625.15 ≤ v < 6.1.965.15 ≤ v < 6.105.15 ≤ v < 6.6.365.15 ≤ v < 6.9.75.16 ≤ v < 6.1.966.2 ≤ v < 6.6.366.7 ≤ v < 6.9.76.10 rc1 6.10 rc2 6.10 rc3 6.10 rc47a3f5b0de3647c854e34269c3332d7a1e902901a

Vendor states this is fixed in 561475d53aa7e4511ee7cdba8728ded81cf1db1c (fixed)

Vendor states this is fixed in 9a3bc8d16e0aacd65c31aaf23a2bced3288a7779 (fixed)

Vendor states this is fixed in af90e3d73dc45778767b2fb6e7edd57ebe34380d (fixed)

Vendor states this is fixed in d62df86c172033679d744f07d89e93e367dd11f6 (fixed)

Vendor states this is fixed in ec4d970b597ee5e17b0d8d73b7875197ce9a04d4 (fixed)

Vendor states this is fixed in 5.15 (unaffected)

Vendor states this is fixed in 5.15.162 (unaffected)

Vendor states this is fixed in 6.1.96 (unaffected)

Vendor states this is fixed in 6.10 (unaffected)

Vendor states this is fixed in 6.6.36 (unaffected)

Vendor states this is fixed in 6.9.7 (unaffected)