{"cve":"CVE-2022-49947","nvd":{"published":"2025-06-18T11:15:21.717","modified":"2026-06-17T05:19:35.923","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbinder: fix alloc->vma_vm_mm null-ptr dereference\n\nSyzbot reported a couple issues introduced by commit 44e602b4e52f\n(\"binder_alloc: add missing mmap_lock calls when using the VMA\"), in\nwhich we attempt to acquire the mmap_lock when alloc->vma_vm_mm has not\nbeen initialized yet.\n\nThis can happen if a binder_proc receives a transaction without having\npreviously called mmap() to setup the binder_proc->alloc space in [1].\nAlso, a similar issue occurs via binder_alloc_print_pages() when we try\nto dump the debugfs binder stats file in [2].\n\nSample of syzbot's crash report:\n  ==================================================================\n  KASAN: null-ptr-deref in range [0x0000000000000128-0x000000000000012f]\n  CPU: 0 PID: 3755 Comm: syz-executor229 Not tainted 6.0.0-rc1-next-20220819-syzkaller #0\n  syz-executor229[3755] cmdline: ./syz-executor2294415195\n  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022\n  RIP: 0010:__lock_acquire+0xd83/0x56d0 kernel/locking/lockdep.c:4923\n  [...]\n  Call Trace:\n   <TASK>\n   lock_acquire kernel/locking/lockdep.c:5666 [inline]\n   lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631\n   down_read+0x98/0x450 kernel/locking/rwsem.c:1499\n   mmap_read_lock include/linux/mmap_lock.h:117 [inline]\n   binder_alloc_new_buf_locked drivers/android/binder_alloc.c:405 [inline]\n   binder_alloc_new_buf+0xa5/0x19e0 drivers/android/binder_alloc.c:593\n   binder_transaction+0x242e/0x9a80 drivers/android/binder.c:3199\n   binder_thread_write+0x664/0x3220 drivers/android/binder.c:3986\n   binder_ioctl_write_read drivers/android/binder.c:5036 [inline]\n   binder_ioctl+0x3470/0x6d00 drivers/android/binder.c:5323\n   vfs_ioctl fs/ioctl.c:51 [inline]\n   __do_sys_ioctl fs/ioctl.c:870 [inline]\n   __se_sys_ioctl fs/ioctl.c:856 [inline]\n   __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856\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+0x63/0xcd\n   [...]\n  ==================================================================\n\nFix these issues by setting up alloc->vma_vm_mm pointer during open()\nand caching directly from current->mm. This guarantees we have a valid\nreference to take the mmap_lock during scenarios described above.\n\n[1] https://syzkaller.appspot.com/bug?extid=f7dc54e5be28950ac459\n[2] https://syzkaller.appspot.com/bug?extid=a75ebe0452711c9e56d9","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/1da52815d5f1b654c89044db0cdc6adce43da1f1","https://git.kernel.org/stable/c/81203ab7a6ef843a2b904a0a494f28c457d44d27","https://git.kernel.org/stable/c/b2a97babb0a510f8921891f9e70c5a5ef33cadac"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:03:23.287444849+00:00"},"epss":{"cve":"CVE-2022-49947","score":0.00231,"percentile":0.13975,"date":"2026-10-31"},"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."]}