CVE-2023-52796
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the Linux kernel, the following vulnerability has been resolved: ipvlan: add ipvlan_route_v6_outbound() helper Inspired by syzbot reports using a stack of multiple ipvlan devices. Reduce stack size needed in ipvlan_process_v6_outbound() by moving the flowi6 struct used for the route lookup in an non inlined helper. ipvlan_route_v6_outbound() needs 120 bytes on the stack, immediately reclaimed. Also make sure ipvlan_process_v4_outbound() is not inlined. We might also have to lower MAX_NEST_DEV, because only syzbot uses setups with more than four stacked devices. BUG: TASK stack guard page was hit at ffffc9000e803ff8 (stack is ffffc9000e804000..ffffc9000e808000) stack guard page: 0000 [#1] SMP KASAN CPU: 0 PID: 13442 Comm: syz-executor.4 Not tainted 6.1.52-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 RIP: 0010:kasan_check_range+0x4/0x2a0 mm/kasan/generic.c:188 Code: 48 01 c6 48 89 c7 e8 db 4e c1 03 31 c0 5d c3 cc 0f 0b eb 02 0f 0b b8 ea ff ff ff 5d c3 cc 00 00 cc cc 00 00 cc cc 55 48 89 e5 <41> 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 a4 01 00 00 48 89 RSP: 0018:ffffc9000e804000 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817e5bf2 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff887c6568 RBP: ffffc9000e804000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92001d0080c R13: dffffc0000000000 R14: ffffffff87e6b100 R15: 0000000000000000 FS: 00007fd0c55826c0(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc9000e803ff8 CR3: 0000000170ef7000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <#DF> </#DF> <TASK> [<ffffffff81f281d1>] __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31 [<ffffffff817e5bf2>] instrument_atomic_read include/linux/instrumented.h:72 [inline] [<ffffffff817e5bf2>] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] [<ffffffff817e5bf2>] cpumask_test_cpu include/linux/cpumask.h:506 [inline] [<ffffffff817e5bf2>] cpu_online include/linux/cpumask.h:1092 [inline] [<ffffffff817e5bf2>] trace_lock_acquire include/trace/events/lock.h:24 [inline] [<ffffffff817e5bf2>] lock_acquire+0xe2/0x590 kernel/locking/lockdep.c:5632 [<ffffffff8563221e>] rcu_lock_acquire+0x2e/0x40 include/linux/rcupdate.h:306 [<ffffffff8561464d>] rcu_read_lock include/linux/rcupdate.h:747 [inline] [<ffffffff8561464d>] ip6_pol_route+0x15d/0x1440 net/ipv6/route.c:2221 [<ffffffff85618120>] ip6_pol_route_output+0x50/0x80 net/ipv6/route.c:2606 [<ffffffff856f65b5>] pol_lookup_func include/net/ip6_fib.h:584 [inline] [<ffffffff856f65b5>] fib6_rule_lookup+0x265/0x620 net/ipv6/fib6_rules.c:116 [<ffffffff85618009>] ip6_route_output_flags_noref+0x2d9/0x3a0 net/ipv6/route.c:2638 [<ffffffff8561821a>] ip6_route_output_flags+0xca/0x340 net/ipv6/route.c:2651 [<ffffffff838bd5a3>] ip6_route_output include/net/ip6_route.h:100 [inline] [<ffffffff838bd5a3>] ipvlan_process_v6_outbound drivers/net/ipvlan/ipvlan_core.c:473 [inline] [<ffffffff838bd5a3>] ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:529 [inline] [<ffffffff838bd5a3>] ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline] [<ffffffff838bd5a3>] ipvlan_queue_xmit+0xc33/0x1be0 drivers/net/ipvlan/ipvlan_core.c:677 [<ffffffff838c2909>] ipvlan_start_xmit+0x49/0x100 drivers/net/ipvlan/ipvlan_main.c:229 [<ffffffff84d03900>] netdev_start_xmit include/linux/netdevice.h:4966 [inline] [<ffffffff84d03900>] xmit_one net/core/dev.c:3644 [inline] [<ffffffff84d03900>] dev_hard_start_xmit+0x320/0x980 net/core/dev.c:3660 [<ffffffff84d080e2>] __dev_queue_xmit+0x16b2/0x3370 net/core/dev.c:4324 [<ffffffff855ce4cd>] dev_queue_xmit include/linux/netdevice.h:3067 [inline] [<ffffffff855ce4cd>] neigh_hh_output include/net/neighbour.h:529 [inline] [<f ---truncated---
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisThe program writes past the bounds of a buffer, overwriting adjacent memory an attacker can turn to their advantage. Crafted input can overwrite control data and redirect execution. Remediation is validating every index and length before a write, plus modern memory-safety mitigations.
General guidance for the out-of-bounds write class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 3.19, < 4.19.300>= 4.20, < 5.4.262>= 5.5, < 5.10.202>= 5.11, < 5.15.140>= 5.16, < 6.1.64>= 6.2, < 6.5.13>= 6.6, < 6.6.3= 6.7CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped4.19.3005.4.2625.10.202
Linux kernel >= 4.19.300, >= 5.4.262, >= 5.10.202, or >= 5.15.140 (depending on your branch)
- Identify the currently running kernel version using 'uname -r' or 'cat /proc/version'
- Determine which version branch your kernel comes from (e.g., 5.15.x, 5.10.x, 5.4.x, 4.19.x)
- Upgrade to a kernel version that includes the fix: for 5.15.x branch use >=5.15.140, for 5.10.x use >=5.10.202, for 5.4.x use >=5.4.262, for 4.19.x use >=4.19.300
- Install the new kernel using your distribution's package manager (e.g., 'apt-get install linux-image-5.15.140-generic' for Ubuntu/Debian, 'yum install kernel-5.15.140' for RHEL/CentOS, or 'dnf install kernel' with appropriate version)
- Reboot the system to load the new kernel: 'sudo reboot'
- Verify the new kernel is running with 'uname -r'
Generated from the published advisory — verify against the referenced sources before acting.
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Free · runs locallyCheck whether your project pulls in CVE-2023-52796 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-52796 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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