CVE-2021-47191 (GCVE-0-2021-47191)

Vulnerability from cvelistv5 – Published: 2024-04-10 18:56 – Updated: 2026-05-11 13:49
VLAI
Title
scsi: scsi_debug: Fix out-of-bound read in resp_readcap16()
Summary
In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_debug: Fix out-of-bound read in resp_readcap16() The following warning was observed running syzkaller: [ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in; [ 3813.830724] program syz-executor not setting count and/or reply_len properly [ 3813.836956] ================================================================== [ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0 [ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549 [ 3813.846612] Call Trace: [ 3813.846995] dump_stack+0x108/0x15f [ 3813.847524] print_address_description+0xa5/0x372 [ 3813.848243] kasan_report.cold+0x236/0x2a8 [ 3813.849439] check_memory_region+0x240/0x270 [ 3813.850094] memcpy+0x30/0x80 [ 3813.850553] sg_copy_buffer+0x157/0x1e0 [ 3813.853032] sg_copy_from_buffer+0x13/0x20 [ 3813.853660] fill_from_dev_buffer+0x135/0x370 [ 3813.854329] resp_readcap16+0x1ac/0x280 [ 3813.856917] schedule_resp+0x41f/0x1630 [ 3813.858203] scsi_debug_queuecommand+0xb32/0x17e0 [ 3813.862699] scsi_dispatch_cmd+0x330/0x950 [ 3813.863329] scsi_request_fn+0xd8e/0x1710 [ 3813.863946] __blk_run_queue+0x10b/0x230 [ 3813.864544] blk_execute_rq_nowait+0x1d8/0x400 [ 3813.865220] sg_common_write.isra.0+0xe61/0x2420 [ 3813.871637] sg_write+0x6c8/0xef0 [ 3813.878853] __vfs_write+0xe4/0x800 [ 3813.883487] vfs_write+0x17b/0x530 [ 3813.884008] ksys_write+0x103/0x270 [ 3813.886268] __x64_sys_write+0x77/0xc0 [ 3813.886841] do_syscall_64+0x106/0x360 [ 3813.887415] entry_SYSCALL_64_after_hwframe+0x44/0xa9 This issue can be reproduced with the following syzkaller log: r0 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x26e1, 0x0) r1 = syz_open_procfs(0xffffffffffffffff, &(0x7f0000000000)='fd/3\x00') open_by_handle_at(r1, &(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000) r2 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x40782) write$binfmt_aout(r2, &(0x7f0000000340)=ANY=[@ANYBLOB="00000000deff000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d"], 0x126) In resp_readcap16() we get "int alloc_len" value -1104926854, and then pass the huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This leads to OOB in sg_copy_buffer(). To solve this issue, define alloc_len as u32.
Severity
No CVSS data available.
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: c65b1445d153a66ca91b00c1f10187e495c17918 , < 3e20cb072679bdb47747ccc8bee3233a4cf0765a (git)
Affected: c65b1445d153a66ca91b00c1f10187e495c17918 , < 5b8bed6464ad6653586e30df046185fd816ad999 (git)
Affected: c65b1445d153a66ca91b00c1f10187e495c17918 , < 4e3ace0051e7e504b55d239daab8789dd89b863c (git)
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Linux Linux Affected: 2.6.18
Unaffected: 0 , < 2.6.18 (semver)
Unaffected: 5.10.82 , ≤ 5.10.* (semver)
Unaffected: 5.15.5 , ≤ 5.15.* (semver)
Unaffected: 5.16 , ≤ * (original_commit_for_fix)
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: scsi_debug: Fix out-of-bound read in resp_readcap16()\n\nThe following warning was observed running syzkaller:\n\n[ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in;\n[ 3813.830724]    program syz-executor not setting count and/or reply_len properly\n[ 3813.836956] ==================================================================\n[ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0\n[ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549\n[ 3813.846612] Call Trace:\n[ 3813.846995]  dump_stack+0x108/0x15f\n[ 3813.847524]  print_address_description+0xa5/0x372\n[ 3813.848243]  kasan_report.cold+0x236/0x2a8\n[ 3813.849439]  check_memory_region+0x240/0x270\n[ 3813.850094]  memcpy+0x30/0x80\n[ 3813.850553]  sg_copy_buffer+0x157/0x1e0\n[ 3813.853032]  sg_copy_from_buffer+0x13/0x20\n[ 3813.853660]  fill_from_dev_buffer+0x135/0x370\n[ 3813.854329]  resp_readcap16+0x1ac/0x280\n[ 3813.856917]  schedule_resp+0x41f/0x1630\n[ 3813.858203]  scsi_debug_queuecommand+0xb32/0x17e0\n[ 3813.862699]  scsi_dispatch_cmd+0x330/0x950\n[ 3813.863329]  scsi_request_fn+0xd8e/0x1710\n[ 3813.863946]  __blk_run_queue+0x10b/0x230\n[ 3813.864544]  blk_execute_rq_nowait+0x1d8/0x400\n[ 3813.865220]  sg_common_write.isra.0+0xe61/0x2420\n[ 3813.871637]  sg_write+0x6c8/0xef0\n[ 3813.878853]  __vfs_write+0xe4/0x800\n[ 3813.883487]  vfs_write+0x17b/0x530\n[ 3813.884008]  ksys_write+0x103/0x270\n[ 3813.886268]  __x64_sys_write+0x77/0xc0\n[ 3813.886841]  do_syscall_64+0x106/0x360\n[ 3813.887415]  entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nThis issue can be reproduced with the following syzkaller log:\n\nr0 = openat(0xffffffffffffff9c, \u0026(0x7f0000000040)=\u0027./file0\\x00\u0027, 0x26e1, 0x0)\nr1 = syz_open_procfs(0xffffffffffffffff, \u0026(0x7f0000000000)=\u0027fd/3\\x00\u0027)\nopen_by_handle_at(r1, \u0026(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000)\nr2 = syz_open_dev$sg(\u0026(0x7f0000000000), 0x0, 0x40782)\nwrite$binfmt_aout(r2, \u0026(0x7f0000000340)=ANY=[@ANYBLOB=\"00000000deff000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d\"], 0x126)\n\nIn resp_readcap16() we get \"int alloc_len\" value -1104926854, and then pass\nthe huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This\nleads to OOB in sg_copy_buffer().\n\nTo solve this issue, define alloc_len as u32."
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    "dateUpdated": "2026-05-11T13:49:44.411Z",
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    "epss": {
      "cve": "CVE-2021-47191",
      "date": "2026-07-14",
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      "percentile": "0.14525"
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      "descriptions": "[{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\nscsi: scsi_debug: Fix out-of-bound read in resp_readcap16()\\n\\nThe following warning was observed running syzkaller:\\n\\n[ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in;\\n[ 3813.830724]    program syz-executor not setting count and/or reply_len properly\\n[ 3813.836956] ==================================================================\\n[ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0\\n[ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549\\n[ 3813.846612] Call Trace:\\n[ 3813.846995]  dump_stack+0x108/0x15f\\n[ 3813.847524]  print_address_description+0xa5/0x372\\n[ 3813.848243]  kasan_report.cold+0x236/0x2a8\\n[ 3813.849439]  check_memory_region+0x240/0x270\\n[ 3813.850094]  memcpy+0x30/0x80\\n[ 3813.850553]  sg_copy_buffer+0x157/0x1e0\\n[ 3813.853032]  sg_copy_from_buffer+0x13/0x20\\n[ 3813.853660]  fill_from_dev_buffer+0x135/0x370\\n[ 3813.854329]  resp_readcap16+0x1ac/0x280\\n[ 3813.856917]  schedule_resp+0x41f/0x1630\\n[ 3813.858203]  scsi_debug_queuecommand+0xb32/0x17e0\\n[ 3813.862699]  scsi_dispatch_cmd+0x330/0x950\\n[ 3813.863329]  scsi_request_fn+0xd8e/0x1710\\n[ 3813.863946]  __blk_run_queue+0x10b/0x230\\n[ 3813.864544]  blk_execute_rq_nowait+0x1d8/0x400\\n[ 3813.865220]  sg_common_write.isra.0+0xe61/0x2420\\n[ 3813.871637]  sg_write+0x6c8/0xef0\\n[ 3813.878853]  __vfs_write+0xe4/0x800\\n[ 3813.883487]  vfs_write+0x17b/0x530\\n[ 3813.884008]  ksys_write+0x103/0x270\\n[ 3813.886268]  __x64_sys_write+0x77/0xc0\\n[ 3813.886841]  do_syscall_64+0x106/0x360\\n[ 3813.887415]  entry_SYSCALL_64_after_hwframe+0x44/0xa9\\n\\nThis issue can be reproduced with the following syzkaller log:\\n\\nr0 = openat(0xffffffffffffff9c, \u0026(0x7f0000000040)=\u0027./file0\\\\x00\u0027, 0x26e1, 0x0)\\nr1 = syz_open_procfs(0xffffffffffffffff, \u0026(0x7f0000000000)=\u0027fd/3\\\\x00\u0027)\\nopen_by_handle_at(r1, \u0026(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000)\\nr2 = syz_open_dev$sg(\u0026(0x7f0000000000), 0x0, 0x40782)\\nwrite$binfmt_aout(r2, \u0026(0x7f0000000340)=ANY=[@ANYBLOB=\\\"00000000deff000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d\\\"], 0x126)\\n\\nIn resp_readcap16() we get \\\"int alloc_len\\\" value -1104926854, and then pass\\nthe huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This\\nleads to OOB in sg_copy_buffer().\\n\\nTo solve this issue, define alloc_len as u32.\"}, {\"lang\": \"es\", \"value\": \"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: scsi: scsi_debug: Se corrige la lectura fuera de los l\\u00edmites en resp_readcap16(). Se observ\\u00f3 la siguiente advertencia al ejecutar syzkaller: [ 3813.830724] sg_write: datos de entrada/salida 65466/242 bytes para el comando SCSI 0x9e-- adivinando datos de entrada; [ 3813.830724] El programa syz-executor no establece count y/o reply_len correctamente [ 3813.836956] ====================================================================== [ 3813.839465] ERROR: KASAN: pila fuera de los l\\u00edmites en sg_copy_buffer+0x157/0x1e0 [ 3813.841773] Lectura de tama\\u00f1o 4096 en la direcci\\u00f3n ffff8883cf80f540 por la tarea syz-executor/1549 [ 3813.846612] Seguimiento de llamadas: [ 3813.846995] dump_stack+0x108/0x15f [ 3813.847524] print_address_description+0xa5/0x372 [ 3813.848243] kasan_report.cold+0x236/0x2a8 [ 3813.849439] check_memory_region+0x240/0x270 [ 3813.850094] memcpy+0x30/0x80 [ 3813.850553] sg_copy_buffer+0x157/0x1e0 [ 3813.853032] sg_copy_from_buffer+0x13/0x20 [ 3813.853660] llenar_desde_buffer_dev+0x135/0x370 [ 3813.854329] resp_readcap16+0x1ac/0x280 [ 3813.856917] schedule_resp+0x41f/0x1630 [ 3813.858203] comando_cola_de_depuraci\\u00f3n_scsi+0xb32/0x17e0 [ 3813.862699] comando_env\\u00edo_scsi+0x330/0x950 [ 3813.863329] funci\\u00f3n_solicitud_scsi+0xd8e/0x1710 [ 3813.863946] cola_ejecuci\\u00f3n_blk+0x10b/0x230 [ 3813.864544] blk_execute_rq_nowait+0x1d8/0x400 [ 3813.865220] sg_common_write.isra.0+0xe61/0x2420 [ 3813.871637] sg_write+0x6c8/0xef0 [ 3813.878853] __vfs_write+0xe4/0x800 [ 3813.883487] vfs_write+0x17b/0x530 [ 3813.884008] ksys_write+0x103/0x270 [ 3813.886268] __x64_sys_write+0x77/0xc0 [ 3813.886841] do_syscall_64+0x106/0x360 [ 3813.887415] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Este problema se puede reproducir con el siguiente registro de syzkaller: r0 = openat(0xffffffffffffff9c, \u0026amp;(0x7f0000000040)=\u0027./file0\\\\x00\u0027, 0x26e1, 0x0) r1 = syz_open_procfs(0xffffffffffffffff, \u0026amp;(0x7f0000000000)=\u0027fd/3\\\\x00\u0027) open_by_handle_at(r1, \u0026amp;(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000) r2 = syz_open_dev$sg(\u0026amp;(0x7f0000000000), 0x0, 0x40782) escribir$binfmt_aout(r2, \u0026amp;(0x7f0000000340)=ANY=[@ANYBLOB=\\\"00000000deff000000000000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d\\\"], 0x126) En resp_readcap16() obtenemos el valor \\\"int alloc_len\\\" -1104926854, y luego pasamos la enorme arr_len se usa para fill_from_dev_buffer(), pero arr solo tiene 32 bytes. Esto genera OOB en sg_copy_buffer(). Para resolver este problema, defina alloc_len como u32.\"}]",
      "id": "CVE-2021-47191",
      "lastModified": "2024-11-21T06:35:35.783",
      "published": "2024-04-10T19:15:47.663",
      "references": "[{\"url\": \"https://git.kernel.org/stable/c/3e20cb072679bdb47747ccc8bee3233a4cf0765a\", \"source\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}, {\"url\": \"https://git.kernel.org/stable/c/4e3ace0051e7e504b55d239daab8789dd89b863c\", \"source\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}, {\"url\": \"https://git.kernel.org/stable/c/5b8bed6464ad6653586e30df046185fd816ad999\", \"source\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}, {\"url\": \"https://git.kernel.org/stable/c/3e20cb072679bdb47747ccc8bee3233a4cf0765a\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://git.kernel.org/stable/c/4e3ace0051e7e504b55d239daab8789dd89b863c\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://git.kernel.org/stable/c/5b8bed6464ad6653586e30df046185fd816ad999\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}]",
      "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "vulnStatus": "Awaiting Analysis"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-47191\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2024-04-10T19:15:47.663\",\"lastModified\":\"2026-06-17T04:16:52.490\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nscsi: scsi_debug: Fix out-of-bound read in resp_readcap16()\\n\\nThe following warning was observed running syzkaller:\\n\\n[ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in;\\n[ 3813.830724]    program syz-executor not setting count and/or reply_len properly\\n[ 3813.836956] ==================================================================\\n[ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0\\n[ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549\\n[ 3813.846612] Call Trace:\\n[ 3813.846995]  dump_stack+0x108/0x15f\\n[ 3813.847524]  print_address_description+0xa5/0x372\\n[ 3813.848243]  kasan_report.cold+0x236/0x2a8\\n[ 3813.849439]  check_memory_region+0x240/0x270\\n[ 3813.850094]  memcpy+0x30/0x80\\n[ 3813.850553]  sg_copy_buffer+0x157/0x1e0\\n[ 3813.853032]  sg_copy_from_buffer+0x13/0x20\\n[ 3813.853660]  fill_from_dev_buffer+0x135/0x370\\n[ 3813.854329]  resp_readcap16+0x1ac/0x280\\n[ 3813.856917]  schedule_resp+0x41f/0x1630\\n[ 3813.858203]  scsi_debug_queuecommand+0xb32/0x17e0\\n[ 3813.862699]  scsi_dispatch_cmd+0x330/0x950\\n[ 3813.863329]  scsi_request_fn+0xd8e/0x1710\\n[ 3813.863946]  __blk_run_queue+0x10b/0x230\\n[ 3813.864544]  blk_execute_rq_nowait+0x1d8/0x400\\n[ 3813.865220]  sg_common_write.isra.0+0xe61/0x2420\\n[ 3813.871637]  sg_write+0x6c8/0xef0\\n[ 3813.878853]  __vfs_write+0xe4/0x800\\n[ 3813.883487]  vfs_write+0x17b/0x530\\n[ 3813.884008]  ksys_write+0x103/0x270\\n[ 3813.886268]  __x64_sys_write+0x77/0xc0\\n[ 3813.886841]  do_syscall_64+0x106/0x360\\n[ 3813.887415]  entry_SYSCALL_64_after_hwframe+0x44/0xa9\\n\\nThis issue can be reproduced with the following syzkaller log:\\n\\nr0 = openat(0xffffffffffffff9c, \u0026(0x7f0000000040)=\u0027./file0\\\\x00\u0027, 0x26e1, 0x0)\\nr1 = syz_open_procfs(0xffffffffffffffff, \u0026(0x7f0000000000)=\u0027fd/3\\\\x00\u0027)\\nopen_by_handle_at(r1, \u0026(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000)\\nr2 = syz_open_dev$sg(\u0026(0x7f0000000000), 0x0, 0x40782)\\nwrite$binfmt_aout(r2, \u0026(0x7f0000000340)=ANY=[@ANYBLOB=\\\"00000000deff000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d\\\"], 0x126)\\n\\nIn resp_readcap16() we get \\\"int alloc_len\\\" value -1104926854, and then pass\\nthe huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This\\nleads to OOB in sg_copy_buffer().\\n\\nTo solve this issue, define alloc_len as u32.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: scsi: scsi_debug: Se corrige la lectura fuera de los l\u00edmites en resp_readcap16(). Se observ\u00f3 la siguiente advertencia al ejecutar syzkaller: [ 3813.830724] sg_write: datos de entrada/salida 65466/242 bytes para el comando SCSI 0x9e-- adivinando datos de entrada; [ 3813.830724] El programa syz-executor no establece count y/o reply_len correctamente [ 3813.836956] ====================================================================== [ 3813.839465] ERROR: KASAN: pila fuera de los l\u00edmites en sg_copy_buffer+0x157/0x1e0 [ 3813.841773] Lectura de tama\u00f1o 4096 en la direcci\u00f3n ffff8883cf80f540 por la tarea syz-executor/1549 [ 3813.846612] Seguimiento de llamadas: [ 3813.846995] dump_stack+0x108/0x15f [ 3813.847524] print_address_description+0xa5/0x372 [ 3813.848243] kasan_report.cold+0x236/0x2a8 [ 3813.849439] check_memory_region+0x240/0x270 [ 3813.850094] memcpy+0x30/0x80 [ 3813.850553] sg_copy_buffer+0x157/0x1e0 [ 3813.853032] sg_copy_from_buffer+0x13/0x20 [ 3813.853660] llenar_desde_buffer_dev+0x135/0x370 [ 3813.854329] resp_readcap16+0x1ac/0x280 [ 3813.856917] schedule_resp+0x41f/0x1630 [ 3813.858203] comando_cola_de_depuraci\u00f3n_scsi+0xb32/0x17e0 [ 3813.862699] comando_env\u00edo_scsi+0x330/0x950 [ 3813.863329] funci\u00f3n_solicitud_scsi+0xd8e/0x1710 [ 3813.863946] cola_ejecuci\u00f3n_blk+0x10b/0x230 [ 3813.864544] blk_execute_rq_nowait+0x1d8/0x400 [ 3813.865220] sg_common_write.isra.0+0xe61/0x2420 [ 3813.871637] sg_write+0x6c8/0xef0 [ 3813.878853] __vfs_write+0xe4/0x800 [ 3813.883487] vfs_write+0x17b/0x530 [ 3813.884008] ksys_write+0x103/0x270 [ 3813.886268] __x64_sys_write+0x77/0xc0 [ 3813.886841] do_syscall_64+0x106/0x360 [ 3813.887415] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Este problema se puede reproducir con el siguiente registro de syzkaller: r0 = openat(0xffffffffffffff9c, \u0026amp;(0x7f0000000040)=\u0027./file0\\\\x00\u0027, 0x26e1, 0x0) r1 = syz_open_procfs(0xffffffffffffffff, \u0026amp;(0x7f0000000000)=\u0027fd/3\\\\x00\u0027) open_by_handle_at(r1, \u0026amp;(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000) r2 = syz_open_dev$sg(\u0026amp;(0x7f0000000000), 0x0, 0x40782) escribir$binfmt_aout(r2, \u0026amp;(0x7f0000000340)=ANY=[@ANYBLOB=\\\"00000000deff000000000000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d\\\"], 0x126) En resp_readcap16() obtenemos el valor \\\"int alloc_len\\\" -1104926854, y luego pasamos la enorme arr_len se usa para fill_from_dev_buffer(), pero arr solo tiene 32 bytes. Esto genera OOB en sg_copy_buffer(). Para resolver este problema, defina alloc_len como u32.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/scsi/scsi_debug.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"c65b1445d153a66ca91b00c1f10187e495c17918\",\"lessThan\":\"3e20cb072679bdb47747ccc8bee3233a4cf0765a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c65b1445d153a66ca91b00c1f10187e495c17918\",\"lessThan\":\"5b8bed6464ad6653586e30df046185fd816ad999\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c65b1445d153a66ca91b00c1f10187e495c17918\",\"lessThan\":\"4e3ace0051e7e504b55d239daab8789dd89b863c\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/scsi/scsi_debug.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.18\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.18\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.82\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.5\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.16\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H\",\"baseScore\":7.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.2}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2024-06-17T18:03:54.717932Z\",\"id\":\"CVE-2021-47191\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-125\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"5.10.82\",\"matchCriteriaId\":\"49103CD7-A3F7-441A-AAF4-11B8B707979D\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.11\",\"versionEndExcluding\":\"5.15.5\",\"matchCriteriaId\":\"2128A085-4C0C-4C1E-9E9C-0DD868E2170F\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/3e20cb072679bdb47747ccc8bee3233a4cf0765a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/4e3ace0051e7e504b55d239daab8789dd89b863c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/5b8bed6464ad6653586e30df046185fd816ad999\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/3e20cb072679bdb47747ccc8bee3233a4cf0765a\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/4e3ace0051e7e504b55d239daab8789dd89b863c\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/5b8bed6464ad6653586e30df046185fd816ad999\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2025-11-21T14:02:25+00:00",
      "cve": "CVE-2021-47191",
      "id": "CVE-2021-47191",
      "initial_release_date": "2021-01-01T00:00:00+00:00",
      "product_status:known_affected": "198",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: scsi: scsi_debug: Fix out-of-bound read in resp_readcap16()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-47191.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://git.kernel.org/stable/c/3e20cb072679bdb47747ccc8bee3233a4cf0765a\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://git.kernel.org/stable/c/5b8bed6464ad6653586e30df046185fd816ad999\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://git.kernel.org/stable/c/4e3ace0051e7e504b55d239daab8789dd89b863c\", \"tags\": [\"x_transferred\"]}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2024-08-04T05:32:07.284Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2021-47191\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2024-06-17T18:03:54.717932Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2024-06-17T18:03:55.961Z\"}}], \"cna\": {\"title\": \"scsi: scsi_debug: Fix out-of-bound read in resp_readcap16()\", \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"c65b1445d153a66ca91b00c1f10187e495c17918\", \"lessThan\": \"3e20cb072679bdb47747ccc8bee3233a4cf0765a\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"c65b1445d153a66ca91b00c1f10187e495c17918\", \"lessThan\": \"5b8bed6464ad6653586e30df046185fd816ad999\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"c65b1445d153a66ca91b00c1f10187e495c17918\", \"lessThan\": \"4e3ace0051e7e504b55d239daab8789dd89b863c\", \"versionType\": \"git\"}], \"programFiles\": [\"drivers/scsi/scsi_debug.c\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"2.6.18\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"2.6.18\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"5.10.82\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.10.*\"}, {\"status\": \"unaffected\", \"version\": \"5.15.5\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.15.*\"}, {\"status\": \"unaffected\", \"version\": \"5.16\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"drivers/scsi/scsi_debug.c\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/3e20cb072679bdb47747ccc8bee3233a4cf0765a\"}, {\"url\": \"https://git.kernel.org/stable/c/5b8bed6464ad6653586e30df046185fd816ad999\"}, {\"url\": \"https://git.kernel.org/stable/c/4e3ace0051e7e504b55d239daab8789dd89b863c\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\nscsi: scsi_debug: Fix out-of-bound read in resp_readcap16()\\n\\nThe following warning was observed running syzkaller:\\n\\n[ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in;\\n[ 3813.830724]    program syz-executor not setting count and/or reply_len properly\\n[ 3813.836956] ==================================================================\\n[ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0\\n[ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549\\n[ 3813.846612] Call Trace:\\n[ 3813.846995]  dump_stack+0x108/0x15f\\n[ 3813.847524]  print_address_description+0xa5/0x372\\n[ 3813.848243]  kasan_report.cold+0x236/0x2a8\\n[ 3813.849439]  check_memory_region+0x240/0x270\\n[ 3813.850094]  memcpy+0x30/0x80\\n[ 3813.850553]  sg_copy_buffer+0x157/0x1e0\\n[ 3813.853032]  sg_copy_from_buffer+0x13/0x20\\n[ 3813.853660]  fill_from_dev_buffer+0x135/0x370\\n[ 3813.854329]  resp_readcap16+0x1ac/0x280\\n[ 3813.856917]  schedule_resp+0x41f/0x1630\\n[ 3813.858203]  scsi_debug_queuecommand+0xb32/0x17e0\\n[ 3813.862699]  scsi_dispatch_cmd+0x330/0x950\\n[ 3813.863329]  scsi_request_fn+0xd8e/0x1710\\n[ 3813.863946]  __blk_run_queue+0x10b/0x230\\n[ 3813.864544]  blk_execute_rq_nowait+0x1d8/0x400\\n[ 3813.865220]  sg_common_write.isra.0+0xe61/0x2420\\n[ 3813.871637]  sg_write+0x6c8/0xef0\\n[ 3813.878853]  __vfs_write+0xe4/0x800\\n[ 3813.883487]  vfs_write+0x17b/0x530\\n[ 3813.884008]  ksys_write+0x103/0x270\\n[ 3813.886268]  __x64_sys_write+0x77/0xc0\\n[ 3813.886841]  do_syscall_64+0x106/0x360\\n[ 3813.887415]  entry_SYSCALL_64_after_hwframe+0x44/0xa9\\n\\nThis issue can be reproduced with the following syzkaller log:\\n\\nr0 = openat(0xffffffffffffff9c, \u0026(0x7f0000000040)=\u0027./file0\\\\x00\u0027, 0x26e1, 0x0)\\nr1 = syz_open_procfs(0xffffffffffffffff, \u0026(0x7f0000000000)=\u0027fd/3\\\\x00\u0027)\\nopen_by_handle_at(r1, \u0026(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000)\\nr2 = syz_open_dev$sg(\u0026(0x7f0000000000), 0x0, 0x40782)\\nwrite$binfmt_aout(r2, \u0026(0x7f0000000340)=ANY=[@ANYBLOB=\\\"00000000deff000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d\\\"], 0x126)\\n\\nIn resp_readcap16() we get \\\"int alloc_len\\\" value -1104926854, and then pass\\nthe huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This\\nleads to OOB in sg_copy_buffer().\\n\\nTo solve this issue, define alloc_len as u32.\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.10.82\", \"versionStartIncluding\": \"2.6.18\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.15.5\", \"versionStartIncluding\": \"2.6.18\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.16\", \"versionStartIncluding\": \"2.6.18\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2025-12-18T11:35:52.721Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2021-47191\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-12-18T11:35:52.721Z\", \"dateReserved\": \"2024-03-25T09:12:14.113Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2024-04-10T18:56:29.455Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.