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Linux KernelOperating system · Linux

CVE-2022-49888

HIGH · 7.8 CVSS v3.1 Published 2025-05-01
Fix available
A fix is available. Upgrade to 5.15.78 / 6.0.8 or later.
See remediation →
80/100
Remediation priority · High
Zero-click Patch available

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 · unedited
In the Linux kernel, the following vulnerability has been resolved: arm64: entry: avoid kprobe recursion The cortex_a76_erratum_1463225_debug_handler() function is called when handling debug exceptions (and synchronous exceptions from BRK instructions), and so is called when a probed function executes. If the compiler does not inline cortex_a76_erratum_1463225_debug_handler(), it can be probed. If cortex_a76_erratum_1463225_debug_handler() is probed, any debug exception or software breakpoint exception will result in recursive exceptions leading to a stack overflow. This can be triggered with the ftrace multiple_probes selftest, and as per the example splat below. This is a regression caused by commit: 6459b8469753e9fe ("arm64: entry: consolidate Cortex-A76 erratum 1463225 workaround") ... which removed the NOKPROBE_SYMBOL() annotation associated with the function. My intent was that cortex_a76_erratum_1463225_debug_handler() would be inlined into its caller, el1_dbg(), which is marked noinstr and cannot be probed. Mark cortex_a76_erratum_1463225_debug_handler() as __always_inline to ensure this. Example splat prior to this patch (with recursive entries elided): | # echo p cortex_a76_erratum_1463225_debug_handler > /sys/kernel/debug/tracing/kprobe_events | # echo p do_el0_svc >> /sys/kernel/debug/tracing/kprobe_events | # echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable | Insufficient stack space to handle exception! | ESR: 0x0000000096000047 -- DABT (current EL) | FAR: 0xffff800009cefff0 | Task stack: [0xffff800009cf0000..0xffff800009cf4000] | IRQ stack: [0xffff800008000000..0xffff800008004000] | Overflow stack: [0xffff00007fbc00f0..0xffff00007fbc10f0] | CPU: 0 PID: 145 Comm: sh Not tainted 6.0.0 #2 | Hardware name: linux,dummy-virt (DT) | pstate: 604003c5 (nZCv DAIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : arm64_enter_el1_dbg+0x4/0x20 | lr : el1_dbg+0x24/0x5c | sp : ffff800009cf0000 | x29: ffff800009cf0000 x28: ffff000002c74740 x27: 0000000000000000 | x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 | x23: 00000000604003c5 x22: ffff80000801745c x21: 0000aaaac95ac068 | x20: 00000000f2000004 x19: ffff800009cf0040 x18: 0000000000000000 | x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 | x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 | x11: 0000000000000010 x10: ffff800008c87190 x9 : ffff800008ca00d0 | x8 : 000000000000003c x7 : 0000000000000000 x6 : 0000000000000000 | x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000000043a4 | x2 : 00000000f2000004 x1 : 00000000f2000004 x0 : ffff800009cf0040 | Kernel panic - not syncing: kernel stack overflow | CPU: 0 PID: 145 Comm: sh Not tainted 6.0.0 #2 | Hardware name: linux,dummy-virt (DT) | Call trace: | dump_backtrace+0xe4/0x104 | show_stack+0x18/0x4c | dump_stack_lvl+0x64/0x7c | dump_stack+0x18/0x38 | panic+0x14c/0x338 | test_taint+0x0/0x2c | panic_bad_stack+0x104/0x118 | handle_bad_stack+0x34/0x48 | __bad_stack+0x78/0x7c | arm64_enter_el1_dbg+0x4/0x20 | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | cortex_a76_erratum_1463225_debug_handler+0x0/0x34 ... | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | cortex_a76_erratum_1463225_debug_handler+0x0/0x34 ... | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | cortex_a76_erratum_1463225_debug_handler+0x0/0x34 | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | do_el0_svc+0x0/0x28 | el0t_64_sync_handler+0x84/0xf0 | el0t_64_sync+0x18c/0x190 | Kernel Offset: disabled | CPU features: 0x0080,00005021,19001080 | Memory Limit: none | ---[ end Kernel panic - not syncing: kernel stack overflow ]--- With this patch, cortex_a76_erratum_1463225_debug_handler() is inlined into el1_dbg(), and el1_dbg() cannot be probed: | # echo p cortex_a76_erratum_1463225_debug_handler > /sys/kernel/debug/tracing/kprobe_events | sh: write error: No such file or directory | # grep -w cortex_a76_errat ---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 analysis
How this class of weakness works · CWE-787

The 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
Linux KernelOperating system
Affected:>= 5.12, < 5.15.78>= 5.16, < 6.0.8= 6.1

CVSS 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 · scoped
Upgrade available Upgrade to 5.15.78 / 6.0.8 or later
Fixed in 5.15.786.0.8
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux Kernel 5.15.78, 6.0.8, or 6.1.1+ (any version >= the respective fixed release for each branch)

  1. 1. Identify the current running Linux kernel version using 'uname -r'
  2. 2. Check if the current version is affected: >= 5.12 and < 5.15.78, OR >= 5.16 and < 6.0.8, OR = 6.1
  3. 3. If affected, schedule a kernel upgrade to a fixed version: 5.15.78+, 6.0.8+, or 6.1.1+
  4. 4. Update the kernel package via distribution's package manager (e.g., apt-get update && apt-get upgrade, yum update, dnf update)
  5. 5. Reboot the system to load the new kernel
  6. 6. Verify the new kernel version is no longer in the affected range using 'uname -r'
Caveat Standard kernel upgrade risks apply - ensure compatibility with custom kernel modules, drivers, and user-space software that may depend on specific kernel APIs

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $3,200. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

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Peer-ranked notes from engineers who’ve handled CVE-2022-49888 in production — separate from our analysis above.

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