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583585e48d
Fix one kernel NULL pointer dereference as below: [ 224.462334] Call Trace: [ 224.462394] __tcp_bpf_recvmsg+0xd3/0x380 [ 224.462441] ? sock_has_perm+0x78/0xa0 [ 224.462463] tcp_bpf_recvmsg+0x12e/0x220 [ 224.462494] inet_recvmsg+0x5b/0xd0 [ 224.462534] __sys_recvfrom+0xc8/0x130 [ 224.462574] ? syscall_trace_enter+0x1df/0x2e0 [ 224.462606] ? __do_page_fault+0x2de/0x500 [ 224.462635] __x64_sys_recvfrom+0x24/0x30 [ 224.462660] do_syscall_64+0x5d/0x1d0 [ 224.462709] entry_SYSCALL_64_after_hwframe+0x65/0xca In commit9974d37ea7("skmsg: Fix invalid last sg check in sk_msg_recvmsg()"), we change last sg check to sg_is_last(), but in sockmap redirection case (without stream_parser/stream_verdict/ skb_verdict), we did not mark the end of the scatterlist. Check the sk_msg_alloc, sk_msg_page_add, and bpf_msg_push_data functions, they all do not mark the end of sg. They are expected to use sg.end for end judgment. So the judgment of '(i != msg_rx->sg.end)' is added back here. Fixes:9974d37ea7("skmsg: Fix invalid last sg check in sk_msg_recvmsg()") Signed-off-by: Liu Jian <liujian56@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20220809094915.150391-1-liujian56@huawei.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.