Bug 2492342 (CVE-2026-53024)
| Summary: | CVE-2026-53024 kernel: greybus: raw: fix use-after-free if write is called after disconnect | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security <prodsec-ir-bot> |
| Status: | NEW --- | QA Contact: | |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | unspecified | CC: | rhel-process-autobot, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's Greybus raw subsystem. A local user could trigger a use-after-free vulnerability by attempting to write to a character device (chardev) after it has been disconnected. This can lead to a kernel panic, resulting in a Denial of Service (DoS) for the system.
|
Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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.