{"id":"AZL-77793","summary":"CVE-2026-23121 affecting package kernel for versions less than 6.6.126.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmISDN: annotate data-race around dev-\u003ework\n\ndev-\u003ework can re read locklessly in mISDN_read()\nand mISDN_poll(). Add READ_ONCE()/WRITE_ONCE() annotations.\n\nBUG: KCSAN: data-race in mISDN_ioctl / mISDN_read\n\nwrite to 0xffff88812d848280 of 4 bytes by task 10864 on cpu 1:\n  misdn_add_timer drivers/isdn/mISDN/timerdev.c:175 [inline]\n  mISDN_ioctl+0x2fb/0x550 drivers/isdn/mISDN/timerdev.c:233\n  vfs_ioctl fs/ioctl.c:51 [inline]\n  __do_sys_ioctl fs/ioctl.c:597 [inline]\n  __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583\n  __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583\n  x64_sys_call+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17\n  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n  do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nread to 0xffff88812d848280 of 4 bytes by task 10857 on cpu 0:\n  mISDN_read+0x1f2/0x470 drivers/isdn/mISDN/timerdev.c:112\n  do_loop_readv_writev fs/read_write.c:847 [inline]\n  vfs_readv+0x3fb/0x690 fs/read_write.c:1020\n  do_readv+0xe7/0x210 fs/read_write.c:1080\n  __do_sys_readv fs/read_write.c:1165 [inline]\n  __se_sys_readv fs/read_write.c:1162 [inline]\n  __x64_sys_readv+0x45/0x50 fs/read_write.c:1162\n  x64_sys_call+0x2831/0x3000 arch/x86/include/generated/asm/syscalls_64.h:20\n  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n  do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nvalue changed: 0x00000000 -\u003e 0x00000001","modified":"2026-08-28T17:47:51.764234984Z","published":"2026-02-14T15:16:07Z","upstream":["CVE-2026-23121"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23121"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.126.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-77793.json"}}],"schema_version":"1.9.0"}