{"id":"CVE-2026-72392","state":"PUBLISHED","title":"ipv6: fib6: fix NULL deref in fib6_walk_continue() on multi-batch dump","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fib6: fix NULL deref in fib6_walk_continue() on multi-batch dump\n\ninet6_dump_fib() saves its progress in cb->args[1] as a positional\nindex within the current hash chain.  Between batches, a concurrent\nfib6_new_table() can insert a new table at the chain head, shifting\nall existing entries.  The saved index then lands on a different\ntable, causing fib6_dump_table() to set w->root to the wrong table\nwhile w->node still points into the previous one.\nfib6_walk_continue() dereferences w->node->parent (NULL) and panics:\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000008\n  RIP: 0010:fib6_walk_continue+0x6e/0x170\n  Call Trace:\n   <TASK>\n   fib6_dump_table.isra.0+0xc5/0x240\n   inet6_dump_fib+0xf6/0x420\n   rtnl_dumpit+0x30/0xa0\n   netlink_dump+0x15b/0x460\n   netlink_recvmsg+0x1d6/0x2a0\n   ____sys_recvmsg+0x17a/0x190\n\nFix by storing tb->tb6_id in cb->args[1] instead of a positional\nindex.  On resume, skip entries until the id matches; a concurrent\nhead-insert can never match the saved id, so the walker always\nresumes on the correct table.","publishedAt":"2026-08-15T05:56:20.463Z","updatedAt":"2026-08-19T16:36:33.417Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"ee73a32dd258d4af66831ff006b771e19812b322","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"89f9c5fee3c64c5cabc34e65599308fd3c879cf9","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"cb90a774a9c6c46961a44949a246fbb61f5f934c","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"27210d433a8c5fe6bf7278a04bbaeb49a81d0290","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"059efb48dd746518898faaa9b965511009b59639","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"d8a01d27873e04bebd357dc87859aa756e0b28b2","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"110ccbd28c9444866fcc84ba96a2ad64fa6e95ae","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"9facb861dc6b9b9ea9793ef5032a9a826f7a4229","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_fib.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.19","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_fib.c"]}],"references":["https://git.kernel.org/stable/c/ee73a32dd258d4af66831ff006b771e19812b322","https://git.kernel.org/stable/c/89f9c5fee3c64c5cabc34e65599308fd3c879cf9","https://git.kernel.org/stable/c/cb90a774a9c6c46961a44949a246fbb61f5f934c","https://git.kernel.org/stable/c/27210d433a8c5fe6bf7278a04bbaeb49a81d0290","https://git.kernel.org/stable/c/059efb48dd746518898faaa9b965511009b59639","https://git.kernel.org/stable/c/d8a01d27873e04bebd357dc87859aa756e0b28b2","https://git.kernel.org/stable/c/110ccbd28c9444866fcc84ba96a2ad64fa6e95ae","https://git.kernel.org/stable/c/9facb861dc6b9b9ea9793ef5032a9a826f7a4229"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72392.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72392","state":"PUBLISHED","datePublished":"2026-08-15T05:56:20.463Z","dateUpdated":"2026-08-19T16:36:33.417Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.924Z"},"containers":{"cna":{"title":"ipv6: fib6: fix NULL deref in fib6_walk_continue() on multi-batch dump","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fib6: fix NULL deref in fib6_walk_continue() on multi-batch dump\n\ninet6_dump_fib() saves its progress in cb->args[1] as a positional\nindex within the current hash chain.  Between batches, a concurrent\nfib6_new_table() can insert a new table at the chain head, shifting\nall existing entries.  The saved index then lands on a different\ntable, causing fib6_dump_table() to set w->root to the wrong table\nwhile w->node still points into the previous one.\nfib6_walk_continue() dereferences w->node->parent (NULL) and panics:\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000008\n  RIP: 0010:fib6_walk_continue+0x6e/0x170\n  Call Trace:\n   <TASK>\n   fib6_dump_table.isra.0+0xc5/0x240\n   inet6_dump_fib+0xf6/0x420\n   rtnl_dumpit+0x30/0xa0\n   netlink_dump+0x15b/0x460\n   netlink_recvmsg+0x1d6/0x2a0\n   ____sys_recvmsg+0x17a/0x190\n\nFix by storing tb->tb6_id in cb->args[1] instead of a positional\nindex.  On resume, skip entries until the id matches; a concurrent\nhead-insert can never match the saved id, so the walker always\nresumes on the correct table."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"ee73a32dd258d4af66831ff006b771e19812b322","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"89f9c5fee3c64c5cabc34e65599308fd3c879cf9","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"cb90a774a9c6c46961a44949a246fbb61f5f934c","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"27210d433a8c5fe6bf7278a04bbaeb49a81d0290","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"059efb48dd746518898faaa9b965511009b59639","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"d8a01d27873e04bebd357dc87859aa756e0b28b2","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"110ccbd28c9444866fcc84ba96a2ad64fa6e95ae","versionType":"git"},{"version":"1b43af5480c351dbcb2eef478bafe179cbeb6e83","status":"affected","lessThan":"9facb861dc6b9b9ea9793ef5032a9a826f7a4229","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_fib.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.19","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_fib.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/ee73a32dd258d4af66831ff006b771e19812b322"},{"url":"https://git.kernel.org/stable/c/89f9c5fee3c64c5cabc34e65599308fd3c879cf9"},{"url":"https://git.kernel.org/stable/c/cb90a774a9c6c46961a44949a246fbb61f5f934c"},{"url":"https://git.kernel.org/stable/c/27210d433a8c5fe6bf7278a04bbaeb49a81d0290"},{"url":"https://git.kernel.org/stable/c/059efb48dd746518898faaa9b965511009b59639"},{"url":"https://git.kernel.org/stable/c/d8a01d27873e04bebd357dc87859aa756e0b28b2"},{"url":"https://git.kernel.org/stable/c/110ccbd28c9444866fcc84ba96a2ad64fa6e95ae"},{"url":"https://git.kernel.org/stable/c/9facb861dc6b9b9ea9793ef5032a9a826f7a4229"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:36:33.417Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.6.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}