From: Alexei Starovoitov Date: Fri, 16 Feb 2024 03:21:39 +0000 (-0800) Subject: Merge branch 'fix-the-read-of-vsyscall-page-through-bpf' X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=54d46c9f581d16ac6adad3c3e61766e02bbfcb60;p=linux.git Merge branch 'fix-the-read-of-vsyscall-page-through-bpf' Hou Tao says: ==================== Fix the read of vsyscall page through bpf From: Hou Tao Hi, As reported by syzboot [1] and [2], when trying to read vsyscall page by using bpf_probe_read_kernel() or bpf_probe_read(), oops may happen. Thomas Gleixner had proposed a test patch [3], but it seems that no formal patch is posted after about one month [4], so I post it instead and add an Originally-by tag in patch #2. Patch #1 makes is_vsyscall_vaddr() being a common helper. Patch #2 fixes the problem by disallowing vsyscall page read for copy_from_kernel_nofault(). Patch #3 adds one test case to ensure the read of vsyscall page through bpf is rejected. Please see individual patches for more details. Comments are always welcome. [1]: https://lore.kernel.org/bpf/CAG48ez06TZft=ATH1qh2c5mpS5BT8UakwNkzi6nvK5_djC-4Nw@mail.gmail.com/ [2]: https://lore.kernel.org/bpf/CABOYnLynjBoFZOf3Z4BhaZkc5hx_kHfsjiW+UWLoB=w33LvScw@mail.gmail.com/ [3]: https://lore.kernel.org/bpf/87r0jwquhv.ffs@tglx/ [4]: https://lore.kernel.org/bpf/e24b125c-8ff4-9031-6c53-67ff2e01f316@huaweicloud.com/ Change Log: v3: * rephrase commit message for patch #1 & #2 (Sohil) * reword comments in copy_from_kernel_nofault_allowed() (Sohil) * add Rvb tag for patch #1 and Acked-by tag for patch #3 (Sohil, Yonghong) v2: https://lore.kernel.org/bpf/20240126115423.3943360-1-houtao@huaweicloud.com/ * move is_vsyscall_vaddr to asm/vsyscall.h instead (Sohil) * elaborate on the reason for disallowing of vsyscall page read in copy_from_kernel_nofault_allowed() (Sohil) * update the commit message of patch #2 to more clearly explain how the oops occurs. (Sohil) * update the commit message of patch #3 to explain the expected return values of various bpf helpers (Yonghong) v1: https://lore.kernel.org/bpf/20240119073019.1528573-1-houtao@huaweicloud.com/ ==================== Link: https://lore.kernel.org/r/20240202103935.3154011-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov --- 54d46c9f581d16ac6adad3c3e61766e02bbfcb60