In the Linux kernel, the following vulnerability has been resolved:
net_sched: fix NULL deref in fifo_set_limit()
syzbot reported another NULL deref in fifo_set_limit() [1]
I could repro the issue with :
unshare -n tc qd add dev lo root handle 1:0 tbf limit 200000 burst 70000 rate 100Mbit tc qd replace dev lo parent 1:0 pfifo_fast tc qd change dev lo root handle 1:0 tbf limit 300000 burst 70000 rate 100Mbit
pfifo_fast does not have a change() operation. Make fifo_set_limit() more robust about this.
[1] BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 1cf99067 P4D 1cf99067 PUD 7ca49067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 1 PID: 14443 Comm: syz-executor959 Not tainted 5.15.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc9000e2f7310 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffffffff8d6ecc00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff888024c27910 RDI: ffff888071e34000 RBP: ffff888071e34000 R08: 0000000000000001 R09: ffffffff8fcfb947 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888024c27910 R13: ffff888071e34018 R14: 0000000000000000 R15: ffff88801ef74800 FS: 00007f321d897700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000000722c3000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fifo_set_limit net/sched/sch_fifo.c:242 [inline] fifo_set_limit+0x198/0x210 net/sched/sch_fifo.c:227 tbf_change+0x6ec/0x16d0 net/sched/sch_tbf.c:418 qdisc_change net/sched/sch_api.c:1332 [inline] tc_modify_qdisc+0xd9a/0x1a60 net/sched/sch_api.c:1634 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5572 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
CVSS Details
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-livepatch-4.14.252-195.481Upgrade python-perf-debuginfoUpgrade kernel-headersUpgrade kernel-livepatch-5.10.75-79.358Upgrade perf-debuginfoUpgrade kernel-debuginfoUpgrade kernelUpgrade kernel-debuginfo-common-x86_64Upgrade python-perfUpgrade bpftool-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-develUpgrade perfUpgrade kernel-tools-develUpgrade kernel-tools-debuginfoUpgrade kernel-toolsUpgrade bpftool | May 21, 2025 | May 21, 2024 |
| Debian | — | Upgrade linux | Jul 30, 2024 | May 21, 2024 |
| Huawei Euleros 2_0_sp9 | — | Upgrade kernel-toolsUpgrade python3-perfUpgrade kernelUpgrade kernel-tools-libs | Oct 8, 2024 | May 21, 2024 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | May 21, 2024 |
| Suse | — | Upgrade kernel-sourceUpgrade kernel-azure-develUpgrade kernel-kvmsmall-develUpgrade kernel-rtUpgrade cluster-md-kmp-azureUpgrade kernel-syms-azureUpgrade kernel-default-base-rebuildUpgrade kselftests-kmp-64kbUpgrade kernel-azure-vdsoUpgrade kernel-azure-livepatch-develUpgrade kernel-symsUpgrade dtb-qcomUpgrade kselftests-kmp-defaultUpgrade ocfs2-kmp-rtUpgrade kernel-devel-rtUpgrade dlm-kmp-64kbUpgrade kernel-64kb-livepatch-develUpgrade kernel-rt-livepatch-develUpgrade kernel-rt-develUpgrade kernel-64kb-develUpgrade gfs2-kmp-64kbUpgrade dtb-amazonUpgrade cluster-md-kmp-defaultUpgrade kernel-64kbUpgrade kernel-devel-azureUpgrade dtb-armUpgrade kernel-64kb-optionalUpgrade kernel-source-azureUpgrade kernel-default-livepatchUpgrade dtb-exynosUpgrade dtb-freescaleUpgrade kernel-kvmsmallUpgrade kernel-default-manUpgrade dtb-lgUpgrade dtb-mediatekUpgrade dtb-apmUpgrade kernel-debug-livepatch-develUpgrade kernel-default-develUpgrade dtb-hisiliconUpgrade kernel-syms-rtUpgrade kernel-default-extraUpgrade dlm-kmp-azureUpgrade gfs2-kmp-rtUpgrade kernel-default-vdsoUpgrade kernel-kvmsmall-livepatch-develUpgrade dtb-amlogicUpgrade dtb-marvellUpgrade kernel-azure-extraUpgrade kernel-macrosUpgrade kernel-rt_debug-vdsoUpgrade kernel-zfcpdumpUpgrade kernel-obs-qaUpgrade kernel-rt-extraUpgrade kernel-azureUpgrade kernel-develUpgrade cluster-md-kmp-rtUpgrade dtb-alteraUpgrade kselftests-kmp-rtUpgrade dlm-kmp-defaultUpgrade kernel-rt-livepatchUpgrade gfs2-kmp-defaultUpgrade dtb-xilinxUpgrade dtb-appleUpgrade dlm-kmp-rtUpgrade reiserfs-kmp-rtUpgrade kernel-kvmsmall-vdsoUpgrade kernel-rt-vdsoUpgrade ocfs2-kmp-defaultUpgrade reiserfs-kmp-azureUpgrade dtb-renesasUpgrade ocfs2-kmp-64kbUpgrade ocfs2-kmp-azureUpgrade kernel-source-vanillaUpgrade kernel-docs-htmlUpgrade kernel-azure-baseUpgrade kernel-docsUpgrade dtb-rockchipUpgrade kernel-defaultUpgrade kernel-default-baseUpgrade dtb-allwinnerUpgrade dtb-socionextUpgrade reiserfs-kmp-defaultUpgrade dtb-nvidiaUpgrade kernel-rt_debug-develUpgrade kernel-debug-develUpgrade reiserfs-kmp-64kbUpgrade gfs2-kmp-azureUpgrade dtb-sprdUpgrade kernel-rt_debugUpgrade kernel-rt_debug-livepatch-develUpgrade kselftests-kmp-azureUpgrade kernel-source-rtUpgrade dtb-amdUpgrade dtb-caviumUpgrade kernel-default-optionalUpgrade dtb-broadcomUpgrade kernel-debugUpgrade kernel-64kb-extraUpgrade kernel-debug-vdsoUpgrade cluster-md-kmp-64kbUpgrade kernel-obs-buildUpgrade kernel-default-livepatch-develUpgrade kernel-rt-optionalUpgrade kernel-azure-optional | Aug 9, 2024 | May 21, 2024 |
| Ubuntu | — | Upgrade linux-awsUpgrade linux-azure-fipsUpgrade linux-aws-fipsUpgrade linux-azure-5.4Upgrade linux-gkeopUpgrade linux-azure-4.15Upgrade linux-hweUpgrade linux-kvmUpgrade linux-hwe-5.4Upgrade linux-ibmUpgrade linux-azureUpgrade linux-gcp-5.4Upgrade linux-oracleUpgrade linux-gcp-4.15Upgrade linux-gcp-fipsUpgrade linux-oracle-5.4Upgrade linux-fipsUpgrade linux-raspiUpgrade linux-aws-5.4Upgrade linux-raspi-5.4Upgrade linux-gcpUpgrade linux-aws-hweUpgrade linuxUpgrade linux-bluefield | Nov 19, 2024 | May 21, 2024 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub