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| author | Jens Axboe <axboe@kernel.dk> | 2025-09-18 13:59:15 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-09-18 13:59:15 -0600 |
| commit | df8922afc37aa2111ca79a216653a629146763ad (patch) | |
| tree | c75fa1b2325c54e460cea5d7732c3dfe659fd190 /io_uring/io_uring.c | |
| parent | 3539b1467e94336d5854ebf976d9627bfb65d6c3 (diff) | |
| download | linux-next-df8922afc37aa2111ca79a216653a629146763ad.tar.gz linux-next-df8922afc37aa2111ca79a216653a629146763ad.zip | |
io_uring/msg_ring: kill alloc_cache for io_kiocb allocations
A recent commit:
fc582cd26e88 ("io_uring/msg_ring: ensure io_kiocb freeing is deferred for RCU")
fixed an issue with not deferring freeing of io_kiocb structs that
msg_ring allocates to after the current RCU grace period. But this only
covers requests that don't end up in the allocation cache. If a request
goes into the alloc cache, it can get reused before it is sane to do so.
A recent syzbot report would seem to indicate that there's something
there, however it may very well just be because of the KASAN poisoning
that the alloc_cache handles manually.
Rather than attempt to make the alloc_cache sane for that use case, just
drop the usage of the alloc_cache for msg_ring request payload data.
Fixes: 50cf5f3842af ("io_uring/msg_ring: add an alloc cache for io_kiocb entries")
Link: https://lore.kernel.org/io-uring/68cc2687.050a0220.139b6.0005.GAE@google.com/
Reported-by: syzbot+baa2e0f4e02df602583e@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/io_uring.c')
| -rw-r--r-- | io_uring/io_uring.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index bcec12256f34..93665cebe9bd 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -290,7 +290,6 @@ static void io_free_alloc_caches(struct io_ring_ctx *ctx) io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free); io_alloc_cache_free(&ctx->rw_cache, io_rw_cache_free); io_alloc_cache_free(&ctx->cmd_cache, io_cmd_cache_free); - io_alloc_cache_free(&ctx->msg_cache, kfree); io_futex_cache_free(ctx); io_rsrc_cache_free(ctx); } @@ -337,9 +336,6 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) ret |= io_alloc_cache_init(&ctx->cmd_cache, IO_ALLOC_CACHE_MAX, sizeof(struct io_async_cmd), sizeof(struct io_async_cmd)); - spin_lock_init(&ctx->msg_lock); - ret |= io_alloc_cache_init(&ctx->msg_cache, IO_ALLOC_CACHE_MAX, - sizeof(struct io_kiocb), 0); ret |= io_futex_cache_init(ctx); ret |= io_rsrc_cache_init(ctx); if (ret) |