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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-80602

perf/x86/amd/lbr: Fix kernel address leakage

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: perf/x86/amd/lbr: Fix kernel address leakage A user-only branch stack can contain branches that originate from the kernel. As a result, kernel addresses are exposed to user space even when PERF_SAMPLE_BRANCH_USER is requested. On AMD processors supporting X86_FEATURE_AMD_LBR_V2, perf can still report SYSRET/ERET entries for which the branch-from addresses are in the kernel. E.g. $ perf record -e cycles -o - -j any,save_type,u -- \ perf bench syscall basic --loop 1000 | \ perf script -i - -F brstack|tr ' ' '\n'| \ grep -E '0x[89a-f][0-9a-f]{15}' ... 0xffffffff81001268/0x717a90a38f1a/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a39157/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a2c628/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a41b60/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a8bef1c30/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a8e4d3c90/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH ... The reason is that the hardware filter only considers the privilege level applicable to the branch target. Extend software filtering to also validate the branch-from addresses against br_sel, so that any branch record whose branch-from address is in the kernel is dropped when PERF_SAMPLE_BRANCH_USER is requested.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • f4f925dae7419fc7a10af539c073871927ce3a24 to < 5be478c1e08981ca91b34de310d7e2638171d9d8affected
  • f4f925dae7419fc7a10af539c073871927ce3a24 to < 208ecca408b1707ad86ea247d3d3e09d3606fc13affected
  • f4f925dae7419fc7a10af539c073871927ce3a24 to < 5ab0eba9c8819506bcb72348fd701f8a9006f95eaffected
  • f4f925dae7419fc7a10af539c073871927ce3a24 to < fb3b76b5ad2ebad63dd76f8b65b624eaf638b73faffected
  • f4f925dae7419fc7a10af539c073871927ce3a24 to < 2a892294b83f541115c94b0bb637f39bef187657affected

Linux Linux

Default version status: affected

  • 6.1affected
  • 0 to < 6.1unaffected
  • 6.6.145 to ≤ 6.6.*unaffected
  • 6.12.97 to ≤ 6.12.*unaffected
  • 6.18.40 to ≤ 6.18.*unaffected
  • 7.1.5 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References