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Zijian ZhangandGreg Kroah-Hartman
1df5d631ba
[ Upstream commit955afd57dc] Found in the test_txmsg_pull in test_sockmap, ``` txmsg_cork = 512; // corking is importrant here opt->iov_length = 3; opt->iov_count = 1; opt->rate = 512; // sendmsg will be invoked 512 times ``` The first sendmsg will send an sk_msg with size 3, and bpf_msg_pull_data will be invoked the first time. sk_msg_reset_curr will reset the copybreak from 3 to 0. In the second sendmsg, since we are in the stage of corking, psock->cork will be reused in func sk_msg_alloc. msg->sg.copybreak is 0 now, the second msg will overwrite the first msg. As a result, we could not pass the data integrity test. The same problem happens in push and pop test. Thus, fix sk_msg_reset_curr to restore the correct copybreak. Fixes:bb9aefde5b("bpf: sockmap, updating the sg structure should also update curr") Signed-off-by: Zijian Zhang <zijianzhang@bytedance.com> Link: https://lore.kernel.org/r/20241106222520.527076-9-zijianzhang@bytedance.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>