{"id":"CVE-2022-49271","summary":"cifs: prevent bad output lengths in smb2_ioctl_query_info()","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 && ./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---","modified":"2026-04-02T08:27:27.034248Z","published":"2025-02-26T01:56:18.148Z","related":["SUSE-SU-2025:1027-1","SUSE-SU-2025:1176-1","SUSE-SU-2025:1183-1","SUSE-SU-2025:1194-1","SUSE-SU-2025:1241-1","SUSE-SU-2025:1263-1","SUSE-SU-2025:1293-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49271.json","cna_assigner":"Linux"},"references":[{"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"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49271.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-49271"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"cfaa1181097f6a1a6f4f6670ebc97848efda0883"},{"fixed":"9963ccea6087268e1275b992dca5d0dd4b938765"},{"fixed":"f143f8334fb9eb2f6c7c15b9da1472d9c965fd84"},{"fixed":"fadddfc1dc3c6f79b21cff4a7e9a6c40b84fbc53"},{"fixed":"7529fbee10d82493c5cb109e51788bf74816d1c0"},{"fixed":"b92e358757b91c2827af112cae9af513f26a3f34"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49271.json"}}],"schema_version":"1.7.5"}