mirror of
https://github.com/Fishwaldo/Star64_linux.git
synced 2025-03-16 04:04:06 +00:00
fuse: fix use after free in fuse_read_interrupt()
[ Upstream commit e1e71c1688
]
There is a potential race between fuse_read_interrupt() and
fuse_request_end().
TASK1
in fuse_read_interrupt(): delete req->intr_entry (while holding
fiq->lock)
TASK2
in fuse_request_end(): req->intr_entry is empty -> skip fiq->lock
wake up TASK3
TASK3
request is freed
TASK1
in fuse_read_interrupt(): dereference req->in.h.unique ***BAM***
Fix by always grabbing fiq->lock if the request was ever interrupted
(FR_INTERRUPTED set) thereby serializing with concurrent
fuse_read_interrupt() calls.
FR_INTERRUPTED is set before the request is queued on fiq->interrupts.
Dequeing the request is done with list_del_init() but FR_INTERRUPTED is not
cleared in this case.
Reported-by: lijiazi <lijiazi@xiaomi.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
parent
bd95a58ccd
commit
cba893f719
1 changed files with 2 additions and 2 deletions
|
@ -288,10 +288,10 @@ void fuse_request_end(struct fuse_req *req)
|
|||
|
||||
/*
|
||||
* test_and_set_bit() implies smp_mb() between bit
|
||||
* changing and below intr_entry check. Pairs with
|
||||
* changing and below FR_INTERRUPTED check. Pairs with
|
||||
* smp_mb() from queue_interrupt().
|
||||
*/
|
||||
if (!list_empty(&req->intr_entry)) {
|
||||
if (test_bit(FR_INTERRUPTED, &req->flags)) {
|
||||
spin_lock(&fiq->lock);
|
||||
list_del_init(&req->intr_entry);
|
||||
spin_unlock(&fiq->lock);
|
||||
|
|
Loading…
Add table
Reference in a new issue