mirror of
https://github.com/torvalds/linux.git
synced 2026-09-22 12:44:03 +02:00
5cbef379a9
dma_req_free() acquires buf_mutex through req->map, drops the mapping
reference with kref_put(), and then dereferences req->map again to unlock
the mutex.
If kref_put() drops the last reference, mport_release_mapping() frees the
mapping, and the subsequent mutex_unlock() dereferences a freed object.
This is a use-after-free.
Fix this by caching map and md before kref_put(), clearing req->map while
holding buf_mutex, and using the cached md for mutex unlocking.
The bug is reachable from userspace via the RapidIO mport character device
interface.
Link: https://lore.kernel.org/20260723235220.588424-1-james010kim@gmail.com
Fixes:
|
||
|---|---|---|
| .. | ||
| devices | ||
| switches | ||
| Kconfig | ||
| Makefile | ||
| rio_cm.c | ||
| rio-access.c | ||
| rio-driver.c | ||
| rio-scan.c | ||
| rio-sysfs.c | ||
| rio.c | ||
| rio.h | ||