{"id":"CVE-2025-38666","state":"PUBLISHED","title":"net: appletalk: Fix use-after-free in AARP proxy probe","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: appletalk: Fix use-after-free in AARP proxy probe\n\nThe AARP proxy‐probe routine (aarp_proxy_probe_network) sends a probe,\nreleases the aarp_lock, sleeps, then re-acquires the lock.  During that\nwindow an expire timer thread (__aarp_expire_timer) can remove and\nkfree() the same entry, leading to a use-after-free.\n\nrace condition:\n\n         cpu 0                          |            cpu 1\n    atalk_sendmsg()                     |   atif_proxy_probe_device()\n    aarp_send_ddp()                     |   aarp_proxy_probe_network()\n    mod_timer()                         |   lock(aarp_lock) // LOCK!!\n    timeout around 200ms                |   alloc(aarp_entry)\n    and then call                       |   proxies[hash] = aarp_entry\n    aarp_expire_timeout()               |   aarp_send_probe()\n                                        |   unlock(aarp_lock) // UNLOCK!!\n    lock(aarp_lock) // LOCK!!           |   msleep(100);\n    __aarp_expire_timer(&proxies[ct])   |\n    free(aarp_entry)                    |\n    unlock(aarp_lock) // UNLOCK!!       |\n                                        |   lock(aarp_lock) // LOCK!!\n                                        |   UAF aarp_entry !!\n\n==================================================================\nBUG: KASAN: slab-use-after-free in aarp_proxy_probe_network+0x560/0x630 net/appletalk/aarp.c:493\nRead of size 4 at addr ffff8880123aa360 by task repro/13278\n\nCPU: 3 UID: 0 PID: 13278 Comm: repro Not tainted 6.15.2 #3 PREEMPT(full)\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:408 [inline]\n print_report+0xc1/0x630 mm/kasan/report.c:521\n kasan_report+0xca/0x100 mm/kasan/report.c:634\n aarp_proxy_probe_network+0x560/0x630 net/appletalk/aarp.c:493\n atif_proxy_probe_device net/appletalk/ddp.c:332 [inline]\n atif_ioctl+0xb58/0x16c0 net/appletalk/ddp.c:857\n atalk_ioctl+0x198/0x2f0 net/appletalk/ddp.c:1818\n sock_do_ioctl+0xdc/0x260 net/socket.c:1190\n sock_ioctl+0x239/0x6a0 net/socket.c:1311\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:906 [inline]\n __se_sys_ioctl fs/ioctl.c:892 [inline]\n __x64_sys_ioctl+0x194/0x200 fs/ioctl.c:892\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xcb/0x250 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n </TASK>\n\nAllocated:\n aarp_alloc net/appletalk/aarp.c:382 [inline]\n aarp_proxy_probe_network+0xd8/0x630 net/appletalk/aarp.c:468\n atif_proxy_probe_device net/appletalk/ddp.c:332 [inline]\n atif_ioctl+0xb58/0x16c0 net/appletalk/ddp.c:857\n atalk_ioctl+0x198/0x2f0 net/appletalk/ddp.c:1818\n\nFreed:\n kfree+0x148/0x4d0 mm/slub.c:4841\n __aarp_expire net/appletalk/aarp.c:90 [inline]\n __aarp_expire_timer net/appletalk/aarp.c:261 [inline]\n aarp_expire_timeout+0x480/0x6e0 net/appletalk/aarp.c:317\n\nThe buggy address belongs to the object at ffff8880123aa300\n which belongs to the cache kmalloc-192 of size 192\nThe buggy address is located 96 bytes inside of\n freed 192-byte region [ffff8880123aa300, ffff8880123aa3c0)\n\nMemory state around the buggy address:\n ffff8880123aa200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n ffff8880123aa280: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc\n>ffff8880123aa300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n                                                       ^\n ffff8880123aa380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc\n ffff8880123aa400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n==================================================================","publishedAt":"2025-08-22T16:02:58.144Z","updatedAt":"2026-05-11T21:32:37.617Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b35694ffabb2af308a1f725d70f60fd8a47d1f3e","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"82d19a70ced28b17a38ebf1b6978c6c7db894979","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"186942d19c0222617ef61f50e1dba91e269a5963","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"2a6209e4649d45fd85d4193abc481911858ffc6f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e4f1564c5b699eb89b3040688fd6b4e57922f1f6","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"5f02ea0f63dd38c41539ea290fcc1693c73aa8e5","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f90b6bb203f3f38bf2b3d976113d51571df9a482","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6c4a92d07b0850342d3becf2e608f805e972467c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/appletalk/aarp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.4.297","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.241","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.190","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.148","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.101","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.41","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.9","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/appletalk/aarp.c"]}],"references":["https://git.kernel.org/stable/c/b35694ffabb2af308a1f725d70f60fd8a47d1f3e","https://git.kernel.org/stable/c/82d19a70ced28b17a38ebf1b6978c6c7db894979","https://git.kernel.org/stable/c/186942d19c0222617ef61f50e1dba91e269a5963","https://git.kernel.org/stable/c/2a6209e4649d45fd85d4193abc481911858ffc6f","https://git.kernel.org/stable/c/e4f1564c5b699eb89b3040688fd6b4e57922f1f6","https://git.kernel.org/stable/c/5f02ea0f63dd38c41539ea290fcc1693c73aa8e5","https://git.kernel.org/stable/c/f90b6bb203f3f38bf2b3d976113d51571df9a482","https://git.kernel.org/stable/c/6c4a92d07b0850342d3becf2e608f805e972467c","https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/38xxx/CVE-2025-38666.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-38666","state":"PUBLISHED","datePublished":"2025-08-22T16:02:58.144Z","dateUpdated":"2026-05-11T21:32:37.617Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T04:51:24.031Z"},"containers":{"cna":{"title":"net: appletalk: Fix use-after-free in AARP proxy probe","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: appletalk: Fix use-after-free in AARP proxy probe\n\nThe AARP proxy‐probe routine (aarp_proxy_probe_network) sends a probe,\nreleases the aarp_lock, sleeps, then re-acquires the lock.  During that\nwindow an expire timer thread (__aarp_expire_timer) can remove and\nkfree() the same entry, leading to a use-after-free.\n\nrace condition:\n\n         cpu 0                          |            cpu 1\n    atalk_sendmsg()                     |   atif_proxy_probe_device()\n    aarp_send_ddp()                     |   aarp_proxy_probe_network()\n    mod_timer()                         |   lock(aarp_lock) // LOCK!!\n    timeout around 200ms                |   alloc(aarp_entry)\n    and then call                       |   proxies[hash] = aarp_entry\n    aarp_expire_timeout()               |   aarp_send_probe()\n                                        |   unlock(aarp_lock) // UNLOCK!!\n    lock(aarp_lock) // LOCK!!           |   msleep(100);\n    __aarp_expire_timer(&proxies[ct])   |\n    free(aarp_entry)                    |\n    unlock(aarp_lock) // UNLOCK!!       |\n                                        |   lock(aarp_lock) // LOCK!!\n                                        |   UAF aarp_entry !!\n\n==================================================================\nBUG: KASAN: slab-use-after-free in aarp_proxy_probe_network+0x560/0x630 net/appletalk/aarp.c:493\nRead of size 4 at addr ffff8880123aa360 by task repro/13278\n\nCPU: 3 UID: 0 PID: 13278 Comm: repro Not tainted 6.15.2 #3 PREEMPT(full)\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:408 [inline]\n print_report+0xc1/0x630 mm/kasan/report.c:521\n kasan_report+0xca/0x100 mm/kasan/report.c:634\n aarp_proxy_probe_network+0x560/0x630 net/appletalk/aarp.c:493\n atif_proxy_probe_device net/appletalk/ddp.c:332 [inline]\n atif_ioctl+0xb58/0x16c0 net/appletalk/ddp.c:857\n atalk_ioctl+0x198/0x2f0 net/appletalk/ddp.c:1818\n sock_do_ioctl+0xdc/0x260 net/socket.c:1190\n sock_ioctl+0x239/0x6a0 net/socket.c:1311\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:906 [inline]\n __se_sys_ioctl fs/ioctl.c:892 [inline]\n __x64_sys_ioctl+0x194/0x200 fs/ioctl.c:892\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xcb/0x250 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n </TASK>\n\nAllocated:\n aarp_alloc net/appletalk/aarp.c:382 [inline]\n aarp_proxy_probe_network+0xd8/0x630 net/appletalk/aarp.c:468\n atif_proxy_probe_device net/appletalk/ddp.c:332 [inline]\n atif_ioctl+0xb58/0x16c0 net/appletalk/ddp.c:857\n atalk_ioctl+0x198/0x2f0 net/appletalk/ddp.c:1818\n\nFreed:\n kfree+0x148/0x4d0 mm/slub.c:4841\n __aarp_expire net/appletalk/aarp.c:90 [inline]\n __aarp_expire_timer net/appletalk/aarp.c:261 [inline]\n aarp_expire_timeout+0x480/0x6e0 net/appletalk/aarp.c:317\n\nThe buggy address belongs to the object at ffff8880123aa300\n which belongs to the cache kmalloc-192 of size 192\nThe buggy address is located 96 bytes inside of\n freed 192-byte region [ffff8880123aa300, ffff8880123aa3c0)\n\nMemory state around the buggy address:\n ffff8880123aa200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n ffff8880123aa280: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc\n>ffff8880123aa300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n                                                       ^\n ffff8880123aa380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc\n ffff8880123aa400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n=================================================================="}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b35694ffabb2af308a1f725d70f60fd8a47d1f3e","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"82d19a70ced28b17a38ebf1b6978c6c7db894979","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"186942d19c0222617ef61f50e1dba91e269a5963","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"2a6209e4649d45fd85d4193abc481911858ffc6f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e4f1564c5b699eb89b3040688fd6b4e57922f1f6","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"5f02ea0f63dd38c41539ea290fcc1693c73aa8e5","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f90b6bb203f3f38bf2b3d976113d51571df9a482","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6c4a92d07b0850342d3becf2e608f805e972467c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/appletalk/aarp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.4.297","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.241","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.190","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.148","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.101","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.41","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.9","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/appletalk/aarp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b35694ffabb2af308a1f725d70f60fd8a47d1f3e"},{"url":"https://git.kernel.org/stable/c/82d19a70ced28b17a38ebf1b6978c6c7db894979"},{"url":"https://git.kernel.org/stable/c/186942d19c0222617ef61f50e1dba91e269a5963"},{"url":"https://git.kernel.org/stable/c/2a6209e4649d45fd85d4193abc481911858ffc6f"},{"url":"https://git.kernel.org/stable/c/e4f1564c5b699eb89b3040688fd6b4e57922f1f6"},{"url":"https://git.kernel.org/stable/c/5f02ea0f63dd38c41539ea290fcc1693c73aa8e5"},{"url":"https://git.kernel.org/stable/c/f90b6bb203f3f38bf2b3d976113d51571df9a482"},{"url":"https://git.kernel.org/stable/c/6c4a92d07b0850342d3becf2e608f805e972467c"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:32:37.617Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.4.297"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.241"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.190"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.41"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.15.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.16"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T17:40:53.180Z"}}]}}}