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CVE-2026-53078

bpf: Fix same-register dst/src OOB read and pointer leak in sock_ops

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.8, 5.9, 5.5, 5.10.270, 5.15.221, and 5 more
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: total

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix same-register dst/src OOB read and pointer leak in sock_ops When a BPF sock_ops program accesses ctx fields with dst_reg == src_reg, the SOCK_OPS_GET_SK() and SOCK_OPS_GET_FIELD() macros fail to zero the destination register in the !fullsock / !locked_tcp_sock path. Both macros borrow a temporary register to check is_fullsock / is_locked_tcp_sock when dst_reg == src_reg, because dst_reg holds the ctx pointer. When the check is false (e.g., TCP_NEW_SYN_RECV state with a request_sock), dst_reg should be zeroed but is not, leaving the stale ctx pointer: • SOCK_OPS_GET_SK: dst_reg retains the ctx pointer, passes NULL checks as PTR_TO_SOCKET_OR_NULL, and can be used as a bogus socket pointer, leading to stack-out-of-bounds access in helpers like bpf_skc_to_tcp6_sock(). • SOCK_OPS_GET_FIELD: dst_reg retains the ctx pointer which the verifier believes is a SCALAR_VALUE, leaking a kernel pointer. Fix both macros by: • Changing JMP_A(1) to JMP_A(2) in the fullsock path to skip the added instruction. • Adding BPF_MOV64_IMM(si->dst_reg, 0) after the temp register restore in the !fullsock path, placed after the restore because dst_reg == src_reg means we need src_reg intact to read ctx->temp.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: total

  3. Record last updated

Affected versions

  • Linux Linux

    From fd09af010788a884de1c39537c288830c3d305db · fixed in db1200ec2c3ddf119d4d9ba67982063df06bbacb; From fd09af010788a884de1c39537c288830c3d305db · fixed in 4c1c5efd9d1d74743d41ce4e1600501b4feb6827; From fd09af010788a884de1c39537c288830c3d305db · fixed in 0e6b30657bbc771f38025c828d722b6162428508; From fd09af010788a884de1c39537c288830c3d305db · fixed in 64eaf4ecda007140ddcdb28e00c48c9c69aaba39; From fd09af010788a884de1c39537c288830c3d305db · fixed in 2a2c98141e0a75f2d4a7d78b0316c88b3da784ac; From fd09af010788a884de1c39537c288830c3d305db · fixed in 22400725de070b787cd6d806c5795370ab46d269; From fd09af010788a884de1c39537c288830c3d305db · fixed in 18e3ffde1822f0b48b1753bf34aa97ce839df1d8; From fd09af010788a884de1c39537c288830c3d305db · fixed in 10f86a2a5c91fc4c4d001960f1c21abe52545ef6; From 5.7.18 · fixed in 5.8; From 5.8.4 · fixed in 5.9; From 5.4.61 · fixed in 5.5

  • Linux Linux

    5.9

  • KernelLinux

    From 5.9.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.101; From 6.13.0 · fixed in 6.18.42; From 6.19.0 · fixed in 7.0.10

References 8

git.kernel.org