{"cve":"CVE-2022-49257","nvd":{"published":"2025-02-26T07:01:02.597","modified":"2026-06-17T05:17:31.643","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nwatch_queue: Fix NULL dereference in error cleanup\n\nIn watch_queue_set_size(), the error cleanup code doesn't take account of\nthe fact that __free_page() can't handle a NULL pointer when trying to free\nup buffer pages that did get allocated.\n\nFix this by only calling __free_page() on the pages actually allocated.\n\nWithout the fix, this can lead to something like the following:\n\nBUG: KASAN: null-ptr-deref in __free_pages+0x1f/0x1b0 mm/page_alloc.c:5473\nRead of size 4 at addr 0000000000000034 by task syz-executor168/3599\n...\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n __kasan_report mm/kasan/report.c:446 [inline]\n kasan_report.cold+0x66/0xdf mm/kasan/report.c:459\n check_region_inline mm/kasan/generic.c:183 [inline]\n kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189\n instrument_atomic_read include/linux/instrumented.h:71 [inline]\n atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]\n page_ref_count include/linux/page_ref.h:67 [inline]\n put_page_testzero include/linux/mm.h:717 [inline]\n __free_pages+0x1f/0x1b0 mm/page_alloc.c:5473\n watch_queue_set_size+0x499/0x630 kernel/watch_queue.c:275\n pipe_ioctl+0xac/0x2b0 fs/pipe.c:632\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:874 [inline]\n __se_sys_ioctl fs/ioctl.c:860 [inline]\n __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x44/0xae","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/112a2f9b0a8457794095a0450598f150724ec456","https://git.kernel.org/stable/c/5ae75b4ed30322b42abaa75ef1b784addfdb7dc9","https://git.kernel.org/stable/c/695c47cea02b9101e2fc2e7d36d552128592b347","https://git.kernel.org/stable/c/a635415a064e77bcfbf43da413fd9dfe0bbed9cb","https://git.kernel.org/stable/c/b6f5ad3e45d19f9c4ee3e8a2aff829f28d68591d"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:48.811064707+00:00"},"epss":{"cve":"CVE-2022-49257","score":0.00261,"percentile":0.17944,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}