In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
bpf: Fix WARNING in bpf_tracing_link_release<\/p>\n
The trampoline could be corrupted by the blindly
\n‘tr->flags = BPF_TRAMP_F_TAIL_CALL_CTX’ in verifier.<\/p>\n
1. A fexit attached to a tail_call_reachable prog. ‘tr->flags’ became
\n ‘BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_TAIL_CALL_CTX’. And, the
\n trampoline would poke the target prog’s nop insn using jmp insn instead
\n of call insn.
\n2. Another fexit loaded with the same tail_call_reachable prog target.
\n ‘tr->flags’ became ‘BPF_TRAMP_F_TAIL_CALL_CTX’.
\n3. Close the first fexit link. Due to no BPF_TRAMP_F_CALL_ORIG in
\n ‘tr->flags’, the trampoline will fail to restore the prog’s nop insn
\n using call insn.<\/p>\n
[ 3.410719] WARNING: kernel\/bpf\/syscall.c:3551 at bpf_tracing_link_release+0x53\/0x60, CPU#1: test_progs\/98
\n…
\n[ 3.428793] bpf_link_free+0x58\/0x130
\n[ 3.429293] bpf_link_release+0x23\/0x30<\/p>\n
Fix the warning by updating ‘tr->flags’ with ‘|=’ and lock.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
bpf: Fix WARNING in bpf_tracing_link_release<\/p>\n
The trampoline could be corrupted by the blindly
\n‘tr->flags = BPF_TRAMP_F_TAIL_CALL_C<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-25854","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/25854","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=25854"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25854"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25854"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}