netfilter: ebtables: zero chainstack array

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: ebtables: zero chainstack array sashiko reports: looking at ebtables table translation, could a sparse cpu_possible_mask lead to an uninitialized pointer free? If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible, but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at CPU 2, the cleanup loop will blindly decrement and call vfree() on newinfo->chainstack[1]. Not a real-world bug, such allocation isn't expected to fail in the first place.

Timeline

1. Jul 25, 2026, 8:50 AM UTCCVE published
2. Oct 16, 2026, 3:40 PM UTCCISA SSVC assessment

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

3. Oct 19, 2026, 8:38 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 2ade612967e2cdfb9290ebcb773f302c82f311fa; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 42bef500d07b5769d916e9122a3e3fa3fd2245ef; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in fc7f105451044501a50cfd530cfa3b472c54acbc; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 9e6c5169db423e51dcc66a73fd15409c0d38e088; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 29bf41a9b59aff9f6197df58641a00037d567ca8; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 9f74d28e903fa4fdf82f870d0aeadddc8196e41c; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 5ee856e4208acafaaaf7b84824d39b78c21345d6; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in cbfe53599eebffd188938ab6774cc41794f6f9d5

• Linux Linux

  2.6.12

• KernelLinux

  From 2.6.12 · fixed in 5.10.261; From 5.11.0 · fixed in 5.15.212; From 5.16.0 · fixed in 6.1.178; From 6.2.0 · fixed in 6.6.145; From 6.7.0 · fixed in 6.12.97; From 6.13.0 · fixed in 6.18.39; From 6.19.0 · fixed in 7.1.4

References 8