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d2e914a4a0
When a dpll_pin is shared across multiple dpll_device instances and
those devices are being unregistered (e.g. during driver module removal),
a NULL pointer dereference can occur in dpll_msg_add_pin_ref_sync().
This happens under the following conditions:
- A pin is registered with two or more dpll devices (dpll_A, dpll_B)
- The pin has ref_sync pairs with other pins
- During unregistration of dpll_A's pins, a ref_sync partner pin is
unregistered first, removing it from dpll_A->pin_refs
- But since the partner pin is still registered with dpll_B, its
dpll_refs is not empty, so dpll_pin_ref_sync_pair_del() does NOT
run and the partner stays in the pin's ref_sync_pins xarray
- When the pin itself is then unregistered from dpll_A, the delete
notification calls dpll_msg_add_pin_ref_sync() which finds the
partner in ref_sync_pins, passes dpll_pin_available() (partner is
still registered with dpll_B), but dpll_pin_on_dpll_priv(dpll_A,
partner) returns NULL because partner was already removed from
dpll_A->pin_refs
- The NULL priv pointer is passed to the driver's ref_sync_get
callback, which dereferences it
BUG: kernel NULL pointer dereference, address: 0000000000000034
Oops: Oops: 0000 [#1] SMP NOPTI
RIP: 0010:zl3073x_dpll_input_pin_ref_sync_get+0x73/0x80 [zl3073x]
Call Trace:
dpll_msg_add_pin_ref_sync+0xb8/0x200
dpll_cmd_pin_get_one+0x3b6/0x4b0
dpll_pin_event_send+0x72/0x140
__dpll_pin_unregister+0x5a/0x2b0
dpll_pin_unregister+0x49/0x70
Fix this by skipping ref_sync pins whose priv pointer cannot be resolved
for the current dpll device.
Fixes:
|
||
|---|---|---|
| .. | ||
| zl3073x | ||
| dpll_core.c | ||
| dpll_core.h | ||
| dpll_netlink.c | ||
| dpll_netlink.h | ||
| dpll_nl.c | ||
| dpll_nl.h | ||
| Kconfig | ||
| Makefile | ||