Description
In the Linux kernel, the following vulnerability has been resolved: sunrpc: route to a populated pool in svc_pool_for_cpu() svc_set_num_threads() spreads the requested threads evenly across the service's pools (base = nrservs / sv_nrpools). When a service runs fewer threads than it has pools -- e.g. an nfsd configured with fewer threads than the host has NUMA nodes while running in "pernode" or "percpu" mode -- the trailing pools are left with no threads at all. svc_xprt_enqueue() selects a pool from the CPU servicing the transport, queues the transport on that pool's sp_xprts, and only wakes a thread from the same pool. Each thread services exclusively its own pool, so a transport that lands on a threadless pool is enqueued on sp_xprts and never picked up: the connection hangs indefinitely. Have svc_pool_for_cpu() skip pools that currently have no threads, falling back to the next populated pool. This trades NUMA locality for a guarantee that the work is actually serviced. sp_nrthreads is only updated under the service mutex; the lockless read here is a best-effort routing hint, so annotate it with data_race().
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
bfd241600a3b0db4fe43c859f1460d0a958d924a to < 9accc25e5af0bac8479f6054e674b2c593c45281affectedbfd241600a3b0db4fe43c859f1460d0a958d924a to < 6f66d38e2a6c78d48723ea17ad86135ec80ca24baffectedbfd241600a3b0db4fe43c859f1460d0a958d924a to < d79d7b9e8acbb53e2d60f6b24afc13e2f15e691faffectedbfd241600a3b0db4fe43c859f1460d0a958d924a to < edb20e8c03aebacb409968c99d046f509c6c485aaffectedbfd241600a3b0db4fe43c859f1460d0a958d924a to < 011479cf9a7657d4a3e7cc42a784ac63df594170affectedbfd241600a3b0db4fe43c859f1460d0a958d924a to < 9d04d64ad192439835ed9884d767353061c3ed6faffectedbfd241600a3b0db4fe43c859f1460d0a958d924a to < 8f766d2d0b4dabf54f8b35812df2b4f481d13316affectedbfd241600a3b0db4fe43c859f1460d0a958d924a to < f6310491c4cdb88af73aa551ec9df1f10a90c709affected
Linux Linux
Default version status: affected
2.6.19affected0 to < 2.6.19unaffected5.10.270 to ≤ 5.10.*unaffected5.15.221 to ≤ 5.15.*unaffected6.1.188 to ≤ 6.1.*unaffected6.6.157 to ≤ 6.6.*unaffected6.12.109 to ≤ 6.12.*unaffected6.18.50 to ≤ 6.18.*unaffected7.2.4 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/9accc25e5af0bac8479f6054e674b2c593c45281 ↗
- https://git.kernel.org/stable/c/6f66d38e2a6c78d48723ea17ad86135ec80ca24b ↗
- https://git.kernel.org/stable/c/d79d7b9e8acbb53e2d60f6b24afc13e2f15e691f ↗
- https://git.kernel.org/stable/c/edb20e8c03aebacb409968c99d046f509c6c485a ↗
- https://git.kernel.org/stable/c/011479cf9a7657d4a3e7cc42a784ac63df594170 ↗
- https://git.kernel.org/stable/c/9d04d64ad192439835ed9884d767353061c3ed6f ↗
- https://git.kernel.org/stable/c/8f766d2d0b4dabf54f8b35812df2b4f481d13316 ↗
- https://git.kernel.org/stable/c/f6310491c4cdb88af73aa551ec9df1f10a90c709 ↗