diff options
author | Kevin Krakauer <krakauer@google.com> | 2021-02-25 13:34:01 -0800 |
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committer | gVisor bot <gvisor-bot@google.com> | 2021-02-25 13:35:44 -0800 |
commit | 38c42bbf4ad2200f0ec72e51d1cfbbd83d782a63 (patch) | |
tree | 10db75d71fa93f329cca518d6a14a0a54a17037b /pkg/sentry/syscalls | |
parent | e50ee26207a99930be966bd48e04f5bccd85cc05 (diff) |
Remove deadlock in raw.endpoint caused by recursive read locking
Prevents the following deadlock:
- Raw packet is sent via e.Write(), which read locks e.mu
- Connect() is called, blocking on write locking e.mu
- The packet is routed to loopback and back to e.HandlePacket(), which read
locks e.mu
Per the atomic.RWMutex documentation, this deadlocks:
"If a goroutine holds a RWMutex for reading and another goroutine might call
Lock, no goroutine should expect to be able to acquire a read lock until the
initial read lock is released. In particular, this prohibits recursive read
locking. This is to ensure that the lock eventually becomes available; a blocked
Lock call excludes new readers from acquiring the lock."
Also, release eps.mu earlier in deliverRawPacket.
PiperOrigin-RevId: 359600926
Diffstat (limited to 'pkg/sentry/syscalls')
0 files changed, 0 insertions, 0 deletions