{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-44946","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-08-21T05:34:56.665Z","datePublished":"2024-08-31T13:22:47.250Z","dateUpdated":"2025-11-03T22:13:51.524Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2025-05-04T09:29:34.530Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nkcm: Serialise kcm_sendmsg() for the same socket.\n\nsyzkaller reported UAF in kcm_release(). [0]\n\nThe scenario is\n\n  1. Thread A builds a skb with MSG_MORE and sets kcm->seq_skb.\n\n  2. Thread A resumes building skb from kcm->seq_skb but is blocked\n     by sk_stream_wait_memory()\n\n  3. Thread B calls sendmsg() concurrently, finishes building kcm->seq_skb\n     and puts the skb to the write queue\n\n  4. Thread A faces an error and finally frees skb that is already in the\n     write queue\n\n  5. kcm_release() does double-free the skb in the write queue\n\nWhen a thread is building a MSG_MORE skb, another thread must not touch it.\n\nLet's add a per-sk mutex and serialise kcm_sendmsg().\n\n[0]:\nBUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline]\nBUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline]\nBUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]\nBUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline]\nBUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691\nRead of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167\n\nCPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G    B              6.8.0-rc5-syzkaller-g9abbc24128bc #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024\nCall trace:\n dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291\n show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0x178/0x518 mm/kasan/report.c:488\n kasan_report+0xd8/0x138 mm/kasan/report.c:601\n __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381\n __skb_unlink include/linux/skbuff.h:2366 [inline]\n __skb_dequeue include/linux/skbuff.h:2385 [inline]\n __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]\n __skb_queue_purge include/linux/skbuff.h:3181 [inline]\n kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691\n __sock_release net/socket.c:659 [inline]\n sock_close+0xa4/0x1e8 net/socket.c:1421\n __fput+0x30c/0x738 fs/file_table.c:376\n ____fput+0x20/0x30 fs/file_table.c:404\n task_work_run+0x230/0x2e0 kernel/task_work.c:180\n exit_task_work include/linux/task_work.h:38 [inline]\n do_exit+0x618/0x1f64 kernel/exit.c:871\n do_group_exit+0x194/0x22c kernel/exit.c:1020\n get_signal+0x1500/0x15ec kernel/signal.c:2893\n do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249\n do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148\n exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]\n exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]\n el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713\n el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730\n el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598\n\nAllocated by task 6166:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x40/0x78 mm/kasan/common.c:68\n kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626\n unpoison_slab_object mm/kasan/common.c:314 [inline]\n __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340\n kasan_slab_alloc include/linux/kasan.h:201 [inline]\n slab_post_alloc_hook mm/slub.c:3813 [inline]\n slab_alloc_node mm/slub.c:3860 [inline]\n kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903\n __alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641\n alloc_skb include/linux/skbuff.h:1296 [inline]\n kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783\n sock_sendmsg_nosec net/socket.c:730 [inline]\n __sock_sendmsg net/socket.c:745 [inline]\n sock_sendmsg+0x220/0x2c0 net/socket.c:768\n splice_to_socket+0x7cc/0xd58 fs/splice.c:889\n do_splice_from fs/splice.c:941 [inline]\n direct_splice_actor+0xec/0x1d8 fs/splice.c:1164\n splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108\n do_splice_direct_actor \n---truncated---"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/kcm.h","net/kcm/kcmsock.c"],"versions":[{"version":"ab7ac4eb9832e32a09f4e8042705484d2fb0aad3","lessThan":"8c9cdbf600143bd6835c8b8351e5ac956da79aec","status":"affected","versionType":"git"},{"version":"ab7ac4eb9832e32a09f4e8042705484d2fb0aad3","lessThan":"6633b17840bf828921254d788ccd15602843fe9b","status":"affected","versionType":"git"},{"version":"ab7ac4eb9832e32a09f4e8042705484d2fb0aad3","lessThan":"eb06c8d3022ce6738711191c89f9b3e9cfb91914","status":"affected","versionType":"git"},{"version":"ab7ac4eb9832e32a09f4e8042705484d2fb0aad3","lessThan":"fa6c23fe6dcac8c8bd63920ee8681292a2bd544e","status":"affected","versionType":"git"},{"version":"ab7ac4eb9832e32a09f4e8042705484d2fb0aad3","lessThan":"72da240aafb142630cf16adc803ccdacb3780849","status":"affected","versionType":"git"},{"version":"ab7ac4eb9832e32a09f4e8042705484d2fb0aad3","lessThan":"00425508f30baa5ab6449a1f478480ca7cffa6da","status":"affected","versionType":"git"},{"version":"ab7ac4eb9832e32a09f4e8042705484d2fb0aad3","lessThan":"9c8d544ed619f704e2b70e63e08ab75630c2ea23","status":"affected","versionType":"git"},{"version":"ab7ac4eb9832e32a09f4e8042705484d2fb0aad3","lessThan":"807067bf014d4a3ae2cc55bd3de16f22a01eb580","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/kcm.h","net/kcm/kcmsock.c"],"versions":[{"version":"4.6","status":"affected"},{"version":"0","lessThan":"4.6","status":"unaffected","versionType":"semver"},{"version":"4.19.321","lessThanOrEqual":"4.19.*","status":"unaffected","versionType":"semver"},{"version":"5.4.283","lessThanOrEqual":"5.4.*","status":"unaffected","versionType":"semver"},{"version":"5.10.225","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.166","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.107","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.48","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.10.7","lessThanOrEqual":"6.10.*","status":"unaffected","versionType":"semver"},{"version":"6.11","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"4.19.321"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.4.283"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.10.225"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.15.166"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.1.107"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.6.48"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.10.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.11"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/8c9cdbf600143bd6835c8b8351e5ac956da79aec"},{"url":"https://git.kernel.org/stable/c/6633b17840bf828921254d788ccd15602843fe9b"},{"url":"https://git.kernel.org/stable/c/eb06c8d3022ce6738711191c89f9b3e9cfb91914"},{"url":"https://git.kernel.org/stable/c/fa6c23fe6dcac8c8bd63920ee8681292a2bd544e"},{"url":"https://git.kernel.org/stable/c/72da240aafb142630cf16adc803ccdacb3780849"},{"url":"https://git.kernel.org/stable/c/00425508f30baa5ab6449a1f478480ca7cffa6da"},{"url":"https://git.kernel.org/stable/c/9c8d544ed619f704e2b70e63e08ab75630c2ea23"},{"url":"https://git.kernel.org/stable/c/807067bf014d4a3ae2cc55bd3de16f22a01eb580"}],"title":"kcm: Serialise kcm_sendmsg() for the same socket.","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-44946","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T15:27:06.483265Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-09-12T17:33:16.399Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"url":"https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T22:13:51.524Z"}}]}}