CVE-2023-53354
What it is
In the Linux kernel, the following vulnerability has been resolved: skbuff: skb_segment, Call zero copy functions before using skbuff frags Commit bf5c25d60861 ("skbuff: in skb_segment, call zerocopy functions once per nskb") added the call to zero copy functions in skb_segment(). The change introduced a bug in skb_segment() because skb_orphan_frags() may possibly change the number of fragments or allocate new fragments altogether leaving nrfrags and frag to point to the old values. This can cause a panic with stacktrace like the one below. [ 193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc [ 193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G O 5.15.123+ #26 [ 193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0 [ 194.021892] Call Trace: [ 194.027422] <TASK> [ 194.072861] tcp_gso_segment+0x107/0x540 [ 194.082031] inet_gso_segment+0x15c/0x3d0 [ 194.090783] skb_mac_gso_segment+0x9f/0x110 [ 194.095016] __skb_gso_segment+0xc1/0x190 [ 194.103131] netem_enqueue+0x290/0xb10 [sch_netem] [ 194.107071] dev_qdisc_enqueue+0x16/0x70 [ 194.110884] __dev_queue_xmit+0x63b/0xb30 [ 194.121670] bond_start_xmit+0x159/0x380 [bonding] [ 194.128506] dev_hard_start_xmit+0xc3/0x1e0 [ 194.131787] __dev_queue_xmit+0x8a0/0xb30 [ 194.138225] macvlan_start_xmit+0x4f/0x100 [macvlan] [ 194.141477] dev_hard_start_xmit+0xc3/0x1e0 [ 194.144622] sch_direct_xmit+0xe3/0x280 [ 194.147748] __dev_queue_xmit+0x54a/0xb30 [ 194.154131] tap_get_user+0x2a8/0x9c0 [tap] [ 194.157358] tap_sendmsg+0x52/0x8e0 [tap] [ 194.167049] handle_tx_zerocopy+0x14e/0x4c0 [vhost_net] [ 194.173631] handle_tx+0xcd/0xe0 [vhost_net] [ 194.176959] vhost_worker+0x76/0xb0 [vhost] [ 194.183667] kthread+0x118/0x140 [ 194.190358] ret_from_fork+0x1f/0x30 [ 194.193670] </TASK> In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags local variable in skb_segment() stale. This resulted in the code hitting i >= nrfrags prematurely and trying to move to next frag_skb using list_skb pointer, which was NULL, and caused kernel panic. Move the call to zero copy functions before using frags and nr_frags.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-476 · NULL pointer dereference
- Record status
- Modified
Affected
- Linux Kernel < 4.19.295
- Linux Kernel < 5.4.257
- Linux Kernel < 5.10.195
- Linux Kernel < 5.15.132
- Linux Kernel < 6.1.53
- Linux Kernel < 6.4.16
- Linux Kernel < 6.5.3
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2023-53354.md and follow it. Check whether this project is affected by CVE-2023-53354. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/04c3eee4e13f60bf6f9a366ad39f88a01a57166e
- https://git.kernel.org/stable/c/2ea35288c83b3d501a88bc17f2df8f176b5cc96f
- https://git.kernel.org/stable/c/6c26ed3c6abe86ddab0510529000b970b05c9b40
- https://git.kernel.org/stable/c/8836c266201c29a5acb4f582227686f47b65ad61
- https://git.kernel.org/stable/c/d44403ec0676317b7f7edf2a035bb219fee3304e
- https://git.kernel.org/stable/c/d5790386595d06ea9decfd9ba5f1ea48cf09aa02
- https://git.kernel.org/stable/c/f99006e840a4dbc8f5a34cecc6b5b26c73ef49bb
- https://git.kernel.org/stable/c/fcab3f661dbfd88e27ddbbe65368f3fa2d823175
References
- https://git.kernel.org/stable/c/04c3eee4e13f60bf6f9a366ad39f88a01a57166e
- https://git.kernel.org/stable/c/2ea35288c83b3d501a88bc17f2df8f176b5cc96f
- https://git.kernel.org/stable/c/6c26ed3c6abe86ddab0510529000b970b05c9b40
- https://git.kernel.org/stable/c/8836c266201c29a5acb4f582227686f47b65ad61
- https://git.kernel.org/stable/c/d44403ec0676317b7f7edf2a035bb219fee3304e
- https://git.kernel.org/stable/c/d5790386595d06ea9decfd9ba5f1ea48cf09aa02
- https://git.kernel.org/stable/c/f99006e840a4dbc8f5a34cecc6b5b26c73ef49bb
- https://git.kernel.org/stable/c/fcab3f661dbfd88e27ddbbe65368f3fa2d823175