fkie_cve-2024-44946
Vulnerability from fkie_nvd
Published
2024-08-31 14:15
Modified
2024-09-04 12:15
Summary
In the Linux kernel, the following vulnerability has been resolved: kcm: Serialise kcm_sendmsg() for the same socket. syzkaller reported UAF in kcm_release(). [0] The scenario is 1. Thread A builds a skb with MSG_MORE and sets kcm->seq_skb. 2. Thread A resumes building skb from kcm->seq_skb but is blocked by sk_stream_wait_memory() 3. Thread B calls sendmsg() concurrently, finishes building kcm->seq_skb and puts the skb to the write queue 4. Thread A faces an error and finally frees skb that is already in the write queue 5. kcm_release() does double-free the skb in the write queue When a thread is building a MSG_MORE skb, another thread must not touch it. Let's add a per-sk mutex and serialise kcm_sendmsg(). [0]: BUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline] BUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline] BUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 Read of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167 CPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G B 6.8.0-rc5-syzkaller-g9abbc24128bc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x178/0x518 mm/kasan/report.c:488 kasan_report+0xd8/0x138 mm/kasan/report.c:601 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __skb_unlink include/linux/skbuff.h:2366 [inline] __skb_dequeue include/linux/skbuff.h:2385 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] __skb_queue_purge include/linux/skbuff.h:3181 [inline] kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 __sock_release net/socket.c:659 [inline] sock_close+0xa4/0x1e8 net/socket.c:1421 __fput+0x30c/0x738 fs/file_table.c:376 ____fput+0x20/0x30 fs/file_table.c:404 task_work_run+0x230/0x2e0 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x618/0x1f64 kernel/exit.c:871 do_group_exit+0x194/0x22c kernel/exit.c:1020 get_signal+0x1500/0x15ec kernel/signal.c:2893 do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 Allocated by task 6166: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626 unpoison_slab_object mm/kasan/common.c:314 [inline] __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903 __alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641 alloc_skb include/linux/skbuff.h:1296 [inline] kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_sendmsg+0x220/0x2c0 net/socket.c:768 splice_to_socket+0x7cc/0xd58 fs/splice.c:889 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0xec/0x1d8 fs/splice.c:1164 splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108 do_splice_direct_actor ---truncated---
Impacted products



{
   configurations: [
      {
         nodes: [
            {
               cpeMatch: [
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                     matchCriteriaId: "90446753-6047-4C19-AD2D-8691C846DDB3",
                     versionEndExcluding: "6.1.107",
                     versionStartIncluding: "4.6",
                     vulnerable: true,
                  },
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                     matchCriteriaId: "9DE9201A-CE6B-4726-BABB-8265EA0F8AE4",
                     versionEndExcluding: "6.6.48",
                     versionStartIncluding: "6.2",
                     vulnerable: true,
                  },
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                     matchCriteriaId: "D2AFDFD1-D95A-4EB7-843B-5E7659518B67",
                     versionEndExcluding: "6.10.7",
                     versionStartIncluding: "6.7",
                     vulnerable: true,
                  },
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*",
                     matchCriteriaId: "8B3CE743-2126-47A3-8B7C-822B502CF119",
                     vulnerable: true,
                  },
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:*",
                     matchCriteriaId: "4DEB27E7-30AA-45CC-8934-B89263EF3551",
                     vulnerable: true,
                  },
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:*",
                     matchCriteriaId: "E0005AEF-856E-47EB-BFE4-90C46899394D",
                     vulnerable: true,
                  },
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:*",
                     matchCriteriaId: "39889A68-6D34-47A6-82FC-CD0BF23D6754",
                     vulnerable: true,
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               ],
               negate: false,
               operator: "OR",
            },
         ],
      },
   ],
   cveTags: [],
   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---",
      },
      {
         lang: "es",
         value: "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: kcm: serializar kcm_sendmsg() para el mismo socket. syzkaller informó de UAF en kcm_release(). [0] El escenario es 1. El hilo A crea un skb con MSG_MORE y establece kcm->seq_skb. 2. El hilo A reanuda la creación de skb desde kcm->seq_skb, pero es bloqueado por sk_stream_wait_memory() 3. El hilo B llama a sendmsg() simultáneamente, termina de crear kcm->seq_skb y coloca el skb en la cola de escritura 4. El hilo A enfrenta un error y finalmente libera el skb que ya está en la cola de escritura 5. kcm_release() libera dos veces el skb en la cola de escritura Cuando un hilo está creando un skb MSG_MORE, otro hilo no debe tocarlo. Agreguemos un mutex por sk y serialicemos kcm_sendmsg(). [0]: BUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline] BUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline] BUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 Read of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167 CPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G B 6.8.0-rc5-syzkaller-g9abbc24128bc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x178/0x518 mm/kasan/report.c:488 kasan_report+0xd8/0x138 mm/kasan/report.c:601 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __skb_unlink include/linux/skbuff.h:2366 [inline] __skb_dequeue include/linux/skbuff.h:2385 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] __skb_queue_purge include/linux/skbuff.h:3181 [inline] kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 __sock_release net/socket.c:659 [inline] sock_close+0xa4/0x1e8 net/socket.c:1421 __fput+0x30c/0x738 fs/file_table.c:376 ____fput+0x20/0x30 fs/file_table.c:404 task_work_run+0x230/0x2e0 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x618/0x1f64 kernel/exit.c:871 do_group_exit+0x194/0x22c kernel/exit.c:1020 get_signal+0x1500/0x15ec kernel/signal.c:2893 do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 Allocated by task 6166: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626 unpoison_slab_object mm/kasan/common.c:314 [inline] __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903 __alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641 alloc_skb include/linux/skbuff.h:1296 [inline] kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_sendmsg+0x220/0x2c0 net/socket.c:768 splice_to_socket+0x7cc/0xd58 fs/splice.c:889 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0xec/0x1d8 fs/splice.c:1164 splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108 do_splice_direct_actor  ---truncado---",
      },
   ],
   id: "CVE-2024-44946",
   lastModified: "2024-09-04T12:15:05.150",
   metrics: {
      cvssMetricV31: [
         {
            cvssData: {
               attackComplexity: "LOW",
               attackVector: "LOCAL",
               availabilityImpact: "HIGH",
               baseScore: 5.5,
               baseSeverity: "MEDIUM",
               confidentialityImpact: "NONE",
               integrityImpact: "NONE",
               privilegesRequired: "LOW",
               scope: "UNCHANGED",
               userInteraction: "NONE",
               vectorString: "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
               version: "3.1",
            },
            exploitabilityScore: 1.8,
            impactScore: 3.6,
            source: "nvd@nist.gov",
            type: "Primary",
         },
      ],
   },
   published: "2024-08-31T14:15:04.320",
   references: [
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/00425508f30baa5ab6449a1f478480ca7cffa6da",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/6633b17840bf828921254d788ccd15602843fe9b",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/72da240aafb142630cf16adc803ccdacb3780849",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/807067bf014d4a3ae2cc55bd3de16f22a01eb580",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/8c9cdbf600143bd6835c8b8351e5ac956da79aec",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/9c8d544ed619f704e2b70e63e08ab75630c2ea23",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/eb06c8d3022ce6738711191c89f9b3e9cfb91914",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/fa6c23fe6dcac8c8bd63920ee8681292a2bd544e",
      },
   ],
   sourceIdentifier: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
   vulnStatus: "Modified",
   weaknesses: [
      {
         description: [
            {
               lang: "en",
               value: "CWE-416",
            },
         ],
         source: "nvd@nist.gov",
         type: "Primary",
      },
   ],
}


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