• Alexander Shishkin's avatar
    intel_th: Don't reference unassigned outputs · 9ed3f222
    Alexander Shishkin authored
    When an output port driver is removed, also remove references to it from
    any masters. Failing to do this causes a NULL ptr dereference when
    configuring another output port:
    
    > BUG: unable to handle kernel NULL pointer dereference at 000000000000000d
    > RIP: 0010:master_attr_store+0x9d/0x160 [intel_th_gth]
    > Call Trace:
    > dev_attr_store+0x1b/0x30
    > sysfs_kf_write+0x3c/0x50
    > kernfs_fop_write+0x125/0x1a0
    > __vfs_write+0x3a/0x190
    > ? __vfs_write+0x5/0x190
    > ? _cond_resched+0x1a/0x50
    > ? rcu_all_qs+0x5/0xb0
    > ? __vfs_write+0x5/0x190
    > vfs_write+0xb8/0x1b0
    > ksys_write+0x55/0xc0
    > __x64_sys_write+0x1a/0x20
    > do_syscall_64+0x5a/0x140
    > entry_SYSCALL_64_after_hwframe+0x44/0xa9
    Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
    Fixes: b27a6a3f ("intel_th: Add Global Trace Hub driver")
    CC: stable@vger.kernel.org # v4.4+
    Reported-by: default avatarAmmy Yi <ammy.yi@intel.com>
    9ed3f222
gth.c 18 KB