Към съдържанието
Търсене

CVE-2026-74618: Linux

Няма оценка

CVSS

Няма данни

Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

Няма потвърждение

Атакува се

Няма данни

Време до експлоатация

    Описание

    Оригинално описание

    In the Linux kernel, the following vulnerability has been resolved: binfmt_misc: don't warn when the mount is completed from another user namespace fsopen() records the caller's user namespace in fc->user_ns and hands back an ordinary file descriptor. Nothing ties the task that calls fsconfig(FSCONFIG_CMD_CREATE) to the task that created the context. The fd is inherited across fork() and exec() and it can be passed over a unix socket. Completing a context from another user namespace is allowed on purpose. vfs_cmd_create() authorizes the create with mount_capable(), which for FS_USERNS_MOUNT checks ns_capable(fc->user_ns, CAP_SYS_ADMIN), and that succeeds for a task holding CAP_SYS_ADMIN in an ancestor of fc->user_ns. So an unprivileged task can reach the WARN_ON() in bm_fill_super(): create a user and a mount namespace in a child, call fsopen("binfmt_misc") there, send the fscontext fd to the parent and let the parent issue FSCONFIG_CMD_CREATE. Both namespaces come from a plain unshare(1) and no capability is needed anywhere: WARNING: fs/binfmt_misc.c:938 at bm_fill_super+0xa2/0xc0 [binfmt_misc] CPU: 15 UID: 1000 PID: 3243382 Comm: fswarn Call Trace: get_tree_keyed+0x7d/0xb0 bm_get_tree+0x34/0x90 [binfmt_misc] vfs_get_tree+0x2a/0x100 vfs_cmd_create+0x60/0xf0 __do_sys_fsconfig+0x4b2/0x500 The child needs the mount namespace because fsopen() itself gates on may_mount(), which asks for CAP_SYS_ADMIN in the user namespace owning the caller's mount namespace. fsconfig() doesn't repeat that check. It is a WARN_ON() and not a WARN_ON_ONCE(), so the condition can be raised in a loop to taint the kernel and flood the log, and it panics a kernel booted with panic_on_warn. Keep refusing the mount and stop warning about it. Nothing in bm_fill_super() depends on the two namespaces matching, it derives everything from sb->s_user_ns.

    Засегнати продукти

    • Linux Linux: 21ca59b365c091d583f36ac753eaa8baf947be6f преди 37cf5cf1320a84a17225a1690547b8a0812ca94e; 21ca59b365c091d583f36ac753eaa8baf947be6f преди 24e95a24f151ce40d5fc1b3a6cefbcda8ded736c; 21ca59b365c091d583f36ac753eaa8baf947be6f преди 047f927f54c6c17593e93aafe82dcb7acdda2a71; 21ca59b365c091d583f36ac753eaa8baf947be6f преди 79fdf39f1a31f88cb3833b6f8091fbf6acdca2c6
    • Linux Linux: 6.7; преди 6.7; 6.12.104 до 6.12.*; 6.18.45 до 6.18.*; 7.1.9 до 7.1.*; от 7.2 нататък

    История

    • 22 август 2026 Публикувано

    Други уязвимости в Linux Linux

    Първоизточници

    CVE-2026-74618: Linux | freedomonline.bg