diff options
| author | Stefano Garzarella <sgarzare@redhat.com> | 2021-09-10 14:45:33 +0200 |
|---|---|---|
| committer | Hanna Reitz <hreitz@redhat.com> | 2021-09-15 15:54:07 +0200 |
| commit | 66fed30c9cd11854fc878a4eceb507e915d7c9cd (patch) | |
| tree | 4dd390c9c889fdd475a96f1f36c4f9a0ac81d5cf /block/mirror.c | |
| parent | 098d983ea5ff1e2b504902d6081074f6b3bf36b8 (diff) | |
block/mirror: fix NULL pointer dereference in mirror_wait_on_conflicts()
In mirror_iteration() we call mirror_wait_on_conflicts() with
`self` parameter set to NULL.
Starting from commit d44dae1a7c we dereference `self` pointer in
mirror_wait_on_conflicts() without checks if it is not NULL.
Backtrace:
Program terminated with signal SIGSEGV, Segmentation fault.
#0 mirror_wait_on_conflicts (self=0x0, s=<optimized out>, offset=<optimized out>, bytes=<optimized out>)
at ../block/mirror.c:172
172 self->waiting_for_op = op;
[Current thread is 1 (Thread 0x7f0908931ec0 (LWP 380249))]
(gdb) bt
#0 mirror_wait_on_conflicts (self=0x0, s=<optimized out>, offset=<optimized out>, bytes=<optimized out>)
at ../block/mirror.c:172
#1 0x00005610c5d9d631 in mirror_run (job=0x5610c76a2c00, errp=<optimized out>) at ../block/mirror.c:491
#2 0x00005610c5d58726 in job_co_entry (opaque=0x5610c76a2c00) at ../job.c:917
#3 0x00005610c5f046c6 in coroutine_trampoline (i0=<optimized out>, i1=<optimized out>)
at ../util/coroutine-ucontext.c:173
#4 0x00007f0909975820 in ?? () at ../sysdeps/unix/sysv/linux/x86_64/__start_context.S:91
from /usr/lib64/libc.so.6
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2001404
Fixes: d44dae1a7c ("block/mirror: fix active mirror dead-lock in mirror_wait_on_conflicts")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20210910124533.288318-1-sgarzare@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Diffstat (limited to 'block/mirror.c')
| -rw-r--r-- | block/mirror.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/block/mirror.c b/block/mirror.c index 98fc66eabf..85b781bc21 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -160,18 +160,25 @@ static void coroutine_fn mirror_wait_on_conflicts(MirrorOp *self, if (ranges_overlap(self_start_chunk, self_nb_chunks, op_start_chunk, op_nb_chunks)) { - /* - * If the operation is already (indirectly) waiting for us, or - * will wait for us as soon as it wakes up, then just go on - * (instead of producing a deadlock in the former case). - */ - if (op->waiting_for_op) { - continue; + if (self) { + /* + * If the operation is already (indirectly) waiting for us, + * or will wait for us as soon as it wakes up, then just go + * on (instead of producing a deadlock in the former case). + */ + if (op->waiting_for_op) { + continue; + } + + self->waiting_for_op = op; } - self->waiting_for_op = op; qemu_co_queue_wait(&op->waiting_requests, NULL); - self->waiting_for_op = NULL; + + if (self) { + self->waiting_for_op = NULL; + } + break; } } |