Zhengchao Shao 234ec0b603 netlink: fix potential sleeping issue in mqueue_flush_file ... I analyze the potential sleeping issue of the following processes: Thread A Thread B ... netlink_create //ref = 1 do_mq_notify ... sock = netlink_getsockbyfilp ... //ref = 2 info->notify_sock = sock; ... ... netlink_sendmsg ... skb = netlink_alloc_large_skb //skb->head is vmalloced ... netlink_unicast ... sk = netlink_getsockbyportid //ref = 3 ... netlink_sendskb ... __netlink_sendskb ... skb_queue_tail //put skb to sk_receive_queue ... sock_put //ref = 2 ... ... ... netlink_release ... deferred_put_nlk_sk //ref = 1 mqueue_flush_file spin_lock remove_notification netlink_sendskb sock_put //ref = 0 sk_free ... __sk_destruct netlink_sock_destruct skb_queue_purge //get skb from sk_receive_queue ... __skb_queue_purge_reason kfree_skb_reason __kfree_skb ... skb_release_all skb_release_head_state netlink_skb_destructor vfree(skb->head) //sleeping while holding spinlock In netlink_sendmsg, if the memory pointed to by skb->head is allocated by vmalloc, and is put to sk_receive_queue queue, also the skb is not freed. When the mqueue executes flush, the sleeping bug will occur. Use vfree_atomic instead of vfree in netlink_skb_destructor to solve the issue. Fixes: c05cdb1b86 ("netlink: allow large data transfers from user-space") Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Link: https://lore.kernel.org/r/20240122011807.2110357-1-shaozhengchao@huawei.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>		2024-01-23 11:21:18 +01:00
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af_netlink.c	netlink: fix potential sleeping issue in mqueue_flush_file	2024-01-23 11:21:18 +01:00
af_netlink.h
diag.c
genetlink.c	genetlink: Use internal flags for multicast groups	2023-12-29 08:43:59 +00:00
Kconfig
Makefile
policy.c