ghsa-8wh8-cr52-wj57
Vulnerability from github
Published
2024-05-17 15:31
Modified
2024-06-27 12:30
Details

In the Linux kernel, the following vulnerability has been resolved:

btrfs: fix information leak in btrfs_ioctl_logical_to_ino()

Syzbot reported the following information leak for in btrfs_ioctl_logical_to_ino():

BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x110 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [inline] _copy_to_user+0xbc/0x110 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [inline] btrfs_ioctl_logical_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499 btrfs_ioctl+0x714/0x1260 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890 x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at: __kmalloc_large_node+0x231/0x370 mm/slub.c:3921 __do_kmalloc_node mm/slub.c:3954 [inline] __kmalloc_node+0xb07/0x1060 mm/slub.c:3973 kmalloc_node include/linux/slab.h:648 [inline] kvmalloc_node+0xc0/0x2d0 mm/util.c:634 kvmalloc include/linux/slab.h:766 [inline] init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779 btrfs_ioctl_logical_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480 btrfs_ioctl+0x714/0x1260 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890 x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Bytes 40-65535 of 65536 are uninitialized Memory access of size 65536 starts at ffff888045a40000

This happens, because we're copying a 'struct btrfs_data_container' back to user-space. This btrfs_data_container is allocated in 'init_data_container()' via kvmalloc(), which does not zero-fill the memory.

Fix this by using kvzalloc() which zeroes out the memory on allocation.

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2024-35849"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-05-17T15:15:21Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix information leak in btrfs_ioctl_logical_to_ino()\n\nSyzbot reported the following information leak for in\nbtrfs_ioctl_logical_to_ino():\n\n  BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]\n  BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x110 lib/usercopy.c:40\n   instrument_copy_to_user include/linux/instrumented.h:114 [inline]\n   _copy_to_user+0xbc/0x110 lib/usercopy.c:40\n   copy_to_user include/linux/uaccess.h:191 [inline]\n   btrfs_ioctl_logical_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499\n   btrfs_ioctl+0x714/0x1260\n   vfs_ioctl fs/ioctl.c:51 [inline]\n   __do_sys_ioctl fs/ioctl.c:904 [inline]\n   __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890\n   __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890\n   x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17\n   do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n   do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n  Uninit was created at:\n   __kmalloc_large_node+0x231/0x370 mm/slub.c:3921\n   __do_kmalloc_node mm/slub.c:3954 [inline]\n   __kmalloc_node+0xb07/0x1060 mm/slub.c:3973\n   kmalloc_node include/linux/slab.h:648 [inline]\n   kvmalloc_node+0xc0/0x2d0 mm/util.c:634\n   kvmalloc include/linux/slab.h:766 [inline]\n   init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779\n   btrfs_ioctl_logical_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480\n   btrfs_ioctl+0x714/0x1260\n   vfs_ioctl fs/ioctl.c:51 [inline]\n   __do_sys_ioctl fs/ioctl.c:904 [inline]\n   __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890\n   __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890\n   x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17\n   do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n   do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n  Bytes 40-65535 of 65536 are uninitialized\n  Memory access of size 65536 starts at ffff888045a40000\n\nThis happens, because we\u0027re copying a \u0027struct btrfs_data_container\u0027 back\nto user-space. This btrfs_data_container is allocated in\n\u0027init_data_container()\u0027 via kvmalloc(), which does not zero-fill the\nmemory.\n\nFix this by using kvzalloc() which zeroes out the memory on allocation.",
  "id": "GHSA-8wh8-cr52-wj57",
  "modified": "2024-06-27T12:30:46Z",
  "published": "2024-05-17T15:31:12Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-35849"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2f7ef5bb4a2f3e481ef05fab946edb97c84f67cf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/30189e54ba80e3209d34cfeea87b848f6ae025e6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3a63cee1a5e14a3e52c19142c61dd5fcb524f6dc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/689efe22e9b5b7d9d523119a9a5c3c17107a0772"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/73db209dcd4ae026021234d40cfcb2fb5b564b86"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8bdbcfaf3eac42f98e5486b3d7e130fa287811f6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e58047553a4e859dafc8d1d901e1de77c9dd922d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fddc19631c51d9c17d43e9f822a7bc403af88d54"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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