Hi, On 12/21/2023 1:50 AM, Yonghong Song wrote: > > On 12/20/23 1:19 AM, Hou Tao wrote: >> Hi, >> >> On 12/14/2023 11:40 AM, xingwei lee wrote: >>> Hello I found a bug in net/bpf in the lastest upstream linux and >>> comfired in the lastest net tree and lastest net bpf titled BUG: >>> unable to handle kernel paging request in bpf_probe_read_compat_str >>> >>> If you fix this issue, please add the following tag to the commit: >>> Reported-by: xingwei Lee <xrivendell7@xxxxxxxxx> >>> >>> kernel: net 9702817384aa4a3700643d0b26e71deac0172cfd / bpf >>> 2f2fee2bf74a7e31d06fc6cb7ba2bd4dd7753c99 >>> Kernel config: >>> https://syzkaller.appspot.com/text?tag=KernelConfig&x=b50bd31249191be8 >>> >>> in the lastest bpf tree, the crash like: >>> >>> TITLE: BUG: unable to handle kernel paging request in >>> bpf_probe_read_compat_str >>> CORRUPTED: false () >>> MAINTAINERS (TO): [akpm@xxxxxxxxxxxxxxxxxxxx linux-mm@xxxxxxxxx] >>> MAINTAINERS (CC): [linux-kernel@xxxxxxxxxxxxxxx] >>> >>> BUG: unable to handle page fault for address: ff0 >> Thanks for the report and reproducer. The output is incomplete. It >> should be: "BUG: unable to handle page fault for address: >> ffffffffff600000". The address is a vsyscall address, so >> handle_page_fault() considers that the fault address is in userspace >> instead of kernel space, and there will be no fix-up for the exception >> and oops happened. Will post a fix and a selftest for it. > > There is a proposed fix here: > > https://lore.kernel.org/bpf/87r0jwquhv.ffs@tglx/ > > Not sure the fix in the above link is merged to some upstream branch > or not. It seems it has not been merged. will ping Thomas later.
