In the Linux kernel, the following vulnerability has been resolved:
xsk: fix usage of multi-buffer BPF helpers for ZC XDP
Currently when packet is shrunk via bpf_xdp_adjust_tail() and memory type is set to MEM_TYPE_XSK_BUFF_POOL, null ptr dereference happens:
[1136314.192256] BUG: kernel NULL pointer dereference, address: 0000000000000034 [1136314.203943] #PF: supervisor read access in kernel mode [1136314.213768] #PF: error_code(0x0000) - not-present page [1136314.223550] PGD 0 P4D 0 [1136314.230684] Oops: 0000 [#1] PREEMPT SMP NOPTI [1136314.239621] CPU: 8 PID: 54203 Comm: xdpsock Not tainted 6.6.0+ #257 [1136314.250469] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [1136314.265615] RIP: 0010:__xdp_return+0x6c/0x210 [1136314.274653] Code: ad 00 48 8b 47 08 49 89 f8 a8 01 0f 85 9b 01 00 00 0f 1f 44 00 00 f0 41 ff 48 34 75 32 4c 89 c7 e9 79 cd 80 ff 83 fe 03 75 17 <f6> 41 34 01 0f 85 02 01 00 00 48 89 cf e9 22 cc 1e 00 e9 3d d2 86 [1136314.302907] RSP: 0018:ffffc900089f8db0 EFLAGS: 00010246 [1136314.312967] RAX: ffffc9003168aed0 RBX: ffff8881c3300000 RCX: 0000000000000000 [1136314.324953] RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffffc9003168c000 [1136314.336929] RBP: 0000000000000ae0 R08: 0000000000000002 R09: 0000000000010000 [1136314.348844] R10: ffffc9000e495000 R11: 0000000000000040 R12: 0000000000000001 [1136314.360706] R13: 0000000000000524 R14: ffffc9003168aec0 R15: 0000000000000001 [1136314.373298] FS: 00007f8df8bbcb80(0000) GS:ffff8897e0e00000(0000) knlGS:0000000000000000 [1136314.386105] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1136314.396532] CR2: 0000000000000034 CR3: 00000001aa912002 CR4: 00000000007706f0 [1136314.408377] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1136314.420173] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [1136314.431890] PKRU: 55555554 [1136314.439143] Call Trace: [1136314.446058] <IRQ> [1136314.452465] ? __die+0x20/0x70 [1136314.459881] ? page_fault_oops+0x15b/0x440 [1136314.468305] ? exc_page_fault+0x6a/0x150 [1136314.476491] ? asm_exc_page_fault+0x22/0x30 [1136314.484927] ? __xdp_return+0x6c/0x210 [1136314.492863] bpf_xdp_adjust_tail+0x155/0x1d0 [1136314.501269] bpf_prog_ccc47ae29d3b6570_xdp_sock_prog+0x15/0x60 [1136314.511263] ice_clean_rx_irq_zc+0x206/0xc60 [ice] [1136314.520222] ? ice_xmit_zc+0x6e/0x150 [ice] [1136314.528506] ice_napi_poll+0x467/0x670 [ice] [1136314.536858] ? ttwu_do_activate.constprop.0+0x8f/0x1a0 [1136314.546010] __napi_poll+0x29/0x1b0 [1136314.553462] net_rx_action+0x133/0x270 [1136314.561619] __do_softirq+0xbe/0x28e [1136314.569303] do_softirq+0x3f/0x60
This comes from __xdp_return() call with xdp_buff argument passed as NULL which is supposed to be consumed by xsk_buff_free() call.
To address this properly, in ZC case, a node that represents the frag being removed has to be pulled out of xskb_list. Introduce appropriate xsk helpers to do such node operation and use them accordingly within bpf_xdp_adjust_tail().
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linux | Jul 27, 2026 | Jul 27, 2026 |
| Redhat_linux | — | Upgrade kernelNo solution existsUpgrade kernel-rt | Dec 5, 2024 | Mar 11, 2024 |
| Suse | — | Upgrade kernel-rt-optionalUpgrade dtb-socionextUpgrade kernel-default-livepatch-develUpgrade kernel-debugUpgrade dtb-renesasUpgrade kernel-azure-extraUpgrade dtb-marvellUpgrade ocfs2-kmp-64kbUpgrade dtb-amazonUpgrade reiserfs-kmp-defaultUpgrade kernel-syms-rtUpgrade kernel-docsUpgrade kernel-zfcpdumpUpgrade kernel-azure-vdsoUpgrade cluster-md-kmp-64kbUpgrade dtb-amdUpgrade kernel-rt_debug-develUpgrade dlm-kmp-rtUpgrade kernel-default-livepatchUpgrade kselftests-kmp-rtUpgrade kernel-default-baseUpgrade kernel-rt-livepatch-develUpgrade kselftests-kmp-azureUpgrade reiserfs-kmp-rtUpgrade kernel-64kbUpgrade dtb-sprdUpgrade kernel-debug-develUpgrade kernel-kvmsmall-livepatch-develUpgrade kernel-develUpgrade gfs2-kmp-defaultUpgrade dlm-kmp-azureUpgrade kernel-rt_debug-vdsoUpgrade dtb-hisiliconUpgrade ocfs2-kmp-azureUpgrade reiserfs-kmp-64kbUpgrade kernel-64kb-extraUpgrade kernel-64kb-livepatch-develUpgrade dtb-broadcomUpgrade kernel-rt_debugUpgrade kernel-rt_debug-livepatch-develUpgrade kernel-symsUpgrade kernel-64kb-optionalUpgrade dlm-kmp-defaultUpgrade kselftests-kmp-defaultUpgrade gfs2-kmp-64kbUpgrade kernel-defaultUpgrade dtb-allwinnerUpgrade kernel-kvmsmall-vdsoUpgrade kernel-docs-htmlUpgrade kernel-source-rtUpgrade ocfs2-kmp-defaultUpgrade dtb-appleUpgrade dtb-freescaleUpgrade kernel-64kb-develUpgrade kernel-default-develUpgrade kernel-source-azureUpgrade cluster-md-kmp-rtUpgrade dtb-nvidiaUpgrade kernel-devel-rtUpgrade dtb-exynosUpgrade gfs2-kmp-rtUpgrade dtb-rockchipUpgrade kernel-source-vanillaUpgrade cluster-md-kmp-azureUpgrade kernel-devel-azureUpgrade dtb-armUpgrade ocfs2-kmp-rtUpgrade dtb-caviumUpgrade dtb-xilinxUpgrade kernel-azure-develUpgrade kernel-azureUpgrade dlm-kmp-64kbUpgrade kselftests-kmp-64kbUpgrade kernel-macrosUpgrade kernel-default-base-rebuildUpgrade kernel-rt-extraUpgrade dtb-alteraUpgrade dtb-amlogicUpgrade kernel-kvmsmallUpgrade kernel-rtUpgrade gfs2-kmp-azureUpgrade dtb-lgUpgrade kernel-default-optionalUpgrade kernel-obs-qaUpgrade kernel-sourceUpgrade kernel-default-extraUpgrade cluster-md-kmp-defaultUpgrade kernel-default-vdsoUpgrade kernel-azure-livepatch-develUpgrade kernel-obs-buildUpgrade kernel-rt-vdsoUpgrade kernel-kvmsmall-develUpgrade kernel-debug-vdsoUpgrade dtb-apmUpgrade dtb-qcomUpgrade dtb-mediatekUpgrade kernel-rt-develUpgrade kernel-debug-livepatch-develUpgrade reiserfs-kmp-azureUpgrade kernel-azure-optionalUpgrade kernel-syms-azure | Jun 24, 2024 | Mar 11, 2024 |
| Ubuntu | — | Upgrade linux-raspi-realtime | Feb 11, 2025 | Mar 11, 2024 |
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