fuse: fix use after free in fuse_read_interrupt()
[ Upstream commit e1e71c16 ] 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>
parent
a1eaaa6b
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