CVE-2026-53024
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk3th percentile — higher than 3% of all known CVEs
Summary
A use-after-free vulnerability was found in the Greybus RAW driver of the Linux kernel. If a user writes to the character device after disconnect has been called, a NULL pointer dereference occurs causing a kernel panic. The issue is due to missing synchronization between write operations and connection destruction.
Risk Assessment
An attacker with local system access can trigger a kernel panic, leading to a denial of service (DoS). The vulnerability does not require special privileges beyond access to the device file.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit adding a rwlock to synchronize write and disconnect).
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: greybus: raw: fix use-after-free if write is called after disconnect If a user writes to the chardev after disconnect has been called, the kernel panics with the following trace (with CONFIG_INIT_ON_FREE_DEFAULT_ON=y): BUG: kernel NULL pointer dereference, address: 0000000000000218 ... Call Trace: <TASK> gb_operation_create_common+0x61/0x180 gb_operation_create_flags+0x28/0xa0 gb_operation_sync_timeout+0x6f/0x100 raw_write+0x7b/0xc7 [gb_raw] vfs_write+0xcf/0x420 ? task_mm_cid_work+0x136/0x220 ksys_write+0x63/0xe0 do_syscall_64+0xa4/0x290 entry_SYSCALL_64_after_hwframe+0x77/0x7f Disconnect calls gb_connection_destroy, which ends up freeing the connection object. When gb_operation_sync is called in the write file operations, its gets a freed connection as parameter and the kernel panics. The gb_connection_destroy cannot be moved out of the disconnect function, as the Greybus subsystem expect all connections belonging to a bundle to be destroyed when disconnect returns. To prevent this bug, use a rw lock to synchronize access between write and disconnect. This guarantees that the write function doesn't try to use a disconnected connection.