* Re: [bug report] Bug: Write fault blocked by KUAP! [not found] ` <CAFj5m9L8ahNYFf-tUAZFKAUzkeyqV-Sx94MxC268XJ-hqHPCig@mail.gmail.com> @ 2026-02-26 12:44 ` Ming Lei 2026-02-26 16:59 ` Caleb Sander Mateos 0 siblings, 1 reply; 4+ messages in thread From: Ming Lei @ 2026-02-26 12:44 UTC (permalink / raw) To: Changhui Zhong, Caleb Sander Mateos Cc: Linux Block Devices, Ming Lei, linuxppc-dev On Thu, Feb 26, 2026 at 6:48 PM Ming Lei <ming.lei@redhat.com> wrote: > > Hi Changhui, > > Thanks for the report! > > Loop Caleb Sander Mateos in. > > Thanks, > > On Thu, Feb 26, 2026 at 6:37 PM Changhui Zhong <czhong@redhat.com> wrote: > > > > Hello, > > > > on the ppc64le arch, I hit the issue below with ublksrv on the latest > > linux-block/for-next, please help check it, and let me know if you > > need any info/test for it. Thanks. > > > > INFO: HEAD of cloned kernel > > commit 37a43fd770f3dcac8f72f3ea909b3e893e2385c9 > > Merge: 13cd9b41227a c1dfbd7e71b0 > > Author: Jens Axboe <axboe@kernel.dk> > > Date: Wed Feb 25 08:37:06 2026 -0700 > > > > Merge branch 'for-7.1/block' into for-next > > > > * for-7.1/block: > > ublk: report BLK_SPLIT_INTERVAL_CAPABLE > > > > reproducer: > > compile and install https://github.com/ublk-org/ublksrv.git > > #echo 0 > /proc/sys/kernel/io_uring_disabled > > #modprobe ublk_drv > > #cd ublksrv > > #make test T=null > > #make test T=loop > > > > dmesg log： > > Feb 26 00:24:30 ibm-p9z-27-lp26 journal: running null/002 > > Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: start ublksrv io > > daemon ublksrvd-0 > > Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: tid 57923: ublk dev > > 0 queue 0 started > > Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: tid 57924: ublk dev > > 0 queue 1 started > > Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083476.4882] platform-linux: do-add-ip6-address[2: > > fe80::8448:a3ff:fe51:f102]: failure 13 (Permission denied - ipv6: IPv6 > > is disabled on this device) > > Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083476.4885] platform-linux: do-add-ip6-address[2: > > 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > > ipv6: IPv6 is disabled on this device) > > Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083476.4938] l3cfg[0f1985ec14299e62,ifindex=2]: unable to > > configure IPv6 route: type unicast fe80::/64 dev 2 metric 1024 mss 0 > > rt-src ipv6ll > > Feb 26 00:24:38 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083478.4938] ipv6ll[95ab7f3fdbfe643d,ifindex=2]: changed: no IPv6 > > link local address to retry after Duplicate Address Detection failures > > (back off) > > Feb 26 00:24:38 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083478.4943] platform-linux: do-add-ip6-address[2: > > 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > > ipv6: IPv6 is disabled on this device) > > Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083488.5034] platform-linux: do-add-ip6-address[2: > > fe80::8448:a3ff:fe51:f102]: failure 13 (Permission denied - ipv6: IPv6 > > is disabled on this device) > > Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083488.5037] platform-linux: do-add-ip6-address[2: > > 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > > ipv6: IPv6 is disabled on this device) > > Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083488.5041] l3cfg[0f1985ec14299e62,ifindex=2]: unable to > > configure IPv6 route: type unicast fe80::/64 dev 2 metric 1024 mss 0 > > rt-src ipv6ll > > Feb 26 00:24:50 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083490.5034] ipv6ll[95ab7f3fdbfe643d,ifindex=2]: changed: no IPv6 > > link local address to retry after Duplicate Address Detection failures > > (back off) > > Feb 26 00:24:50 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > [1772083490.5039] platform-linux: do-add-ip6-address[2: > > 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > > ipv6: IPv6 is disabled on this device) > > Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: Kernel attempted to read user > > page (7fff81210000) - exploit attempt? (uid: 0) > > Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: ------------[ cut here ]------------ > > Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: Bug: Read fault blocked by KUAP! > > Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: WARNING: > > arch/powerpc/mm/fault.c:231 at bad_kernel_fault.isra.0+0xc8/0x2c0, > > CPU#5: lt-ublk.null/57924 oops, it shouldn't be related with `ublk: report BLK_SPLIT_INTERVAL_CAPABLE`, Perhaps one issue lies in the ppcle64 architecture code. I will find one ppc box and try to reproduce this. Thanks, ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [bug report] Bug: Write fault blocked by KUAP! 2026-02-26 12:44 ` [bug report] Bug: Write fault blocked by KUAP! Ming Lei @ 2026-02-26 16:59 ` Caleb Sander Mateos 2026-02-26 18:57 ` Christophe Leroy (CS GROUP) 0 siblings, 1 reply; 4+ messages in thread From: Caleb Sander Mateos @ 2026-02-26 16:59 UTC (permalink / raw) To: Ming Lei; +Cc: Changhui Zhong, Linux Block Devices, linuxppc-dev On Thu, Feb 26, 2026 at 4:44 AM Ming Lei <ming.lei@redhat.com> wrote: > > On Thu, Feb 26, 2026 at 6:48 PM Ming Lei <ming.lei@redhat.com> wrote: > > > > Hi Changhui, > > > > Thanks for the report! > > > > Loop Caleb Sander Mateos in. > > > > Thanks, > > > > On Thu, Feb 26, 2026 at 6:37 PM Changhui Zhong <czhong@redhat.com> wrote: > > > > > > Hello, > > > > > > on the ppc64le arch, I hit the issue below with ublksrv on the latest > > > linux-block/for-next, please help check it, and let me know if you > > > need any info/test for it. Thanks. > > > > > > INFO: HEAD of cloned kernel > > > commit 37a43fd770f3dcac8f72f3ea909b3e893e2385c9 > > > Merge: 13cd9b41227a c1dfbd7e71b0 > > > Author: Jens Axboe <axboe@kernel.dk> > > > Date: Wed Feb 25 08:37:06 2026 -0700 > > > > > > Merge branch 'for-7.1/block' into for-next > > > > > > * for-7.1/block: > > > ublk: report BLK_SPLIT_INTERVAL_CAPABLE > > > > > > reproducer: > > > compile and install https://github.com/ublk-org/ublksrv.git > > > #echo 0 > /proc/sys/kernel/io_uring_disabled > > > #modprobe ublk_drv > > > #cd ublksrv > > > #make test T=null > > > #make test T=loop > > > > > > dmesg log： > > > Feb 26 00:24:30 ibm-p9z-27-lp26 journal: running null/002 > > > Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: start ublksrv io > > > daemon ublksrvd-0 > > > Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: tid 57923: ublk dev > > > 0 queue 0 started > > > Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: tid 57924: ublk dev > > > 0 queue 1 started > > > Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083476.4882] platform-linux: do-add-ip6-address[2: > > > fe80::8448:a3ff:fe51:f102]: failure 13 (Permission denied - ipv6: IPv6 > > > is disabled on this device) > > > Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083476.4885] platform-linux: do-add-ip6-address[2: > > > 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > > > ipv6: IPv6 is disabled on this device) > > > Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083476.4938] l3cfg[0f1985ec14299e62,ifindex=2]: unable to > > > configure IPv6 route: type unicast fe80::/64 dev 2 metric 1024 mss 0 > > > rt-src ipv6ll > > > Feb 26 00:24:38 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083478.4938] ipv6ll[95ab7f3fdbfe643d,ifindex=2]: changed: no IPv6 > > > link local address to retry after Duplicate Address Detection failures > > > (back off) > > > Feb 26 00:24:38 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083478.4943] platform-linux: do-add-ip6-address[2: > > > 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > > > ipv6: IPv6 is disabled on this device) > > > Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083488.5034] platform-linux: do-add-ip6-address[2: > > > fe80::8448:a3ff:fe51:f102]: failure 13 (Permission denied - ipv6: IPv6 > > > is disabled on this device) > > > Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083488.5037] platform-linux: do-add-ip6-address[2: > > > 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > > > ipv6: IPv6 is disabled on this device) > > > Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083488.5041] l3cfg[0f1985ec14299e62,ifindex=2]: unable to > > > configure IPv6 route: type unicast fe80::/64 dev 2 metric 1024 mss 0 > > > rt-src ipv6ll > > > Feb 26 00:24:50 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083490.5034] ipv6ll[95ab7f3fdbfe643d,ifindex=2]: changed: no IPv6 > > > link local address to retry after Duplicate Address Detection failures > > > (back off) > > > Feb 26 00:24:50 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > > > [1772083490.5039] platform-linux: do-add-ip6-address[2: > > > 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > > > ipv6: IPv6 is disabled on this device) > > > Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: Kernel attempted to read user > > > page (7fff81210000) - exploit attempt? (uid: 0) > > > Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: ------------[ cut here ]------------ > > > Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: Bug: Read fault blocked by KUAP! > > > Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: WARNING: > > > arch/powerpc/mm/fault.c:231 at bad_kernel_fault.isra.0+0xc8/0x2c0, > > > CPU#5: lt-ublk.null/57924 > > oops, it shouldn't be related with `ublk: report BLK_SPLIT_INTERVAL_CAPABLE`, > Perhaps one issue lies in the ppcle64 architecture code. Agreed, the "Kernel attempted to read user page" error seems incorrect. The call trace shows this is in copy_from_iter(), so reading a user page is expected. I too would be suspicious of the powerpc copy_from_iter() implementation. Best, Caleb ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [bug report] Bug: Write fault blocked by KUAP! 2026-02-26 16:59 ` Caleb Sander Mateos @ 2026-02-26 18:57 ` Christophe Leroy (CS GROUP) 2026-02-28 2:57 ` Changhui Zhong 0 siblings, 1 reply; 4+ messages in thread From: Christophe Leroy (CS GROUP) @ 2026-02-26 18:57 UTC (permalink / raw) To: Caleb Sander Mateos, Ming Lei Cc: Changhui Zhong, Linux Block Devices, linuxppc-dev Le 26/02/2026 à 17:59, Caleb Sander Mateos a écrit : > On Thu, Feb 26, 2026 at 4:44 AM Ming Lei <ming.lei@redhat.com> wrote: >> >> On Thu, Feb 26, 2026 at 6:48 PM Ming Lei <ming.lei@redhat.com> wrote: >>> >>> Hi Changhui, >>> >>> Thanks for the report! >>> >>> Loop Caleb Sander Mateos in. >>> >>> Thanks, >>> >>> On Thu, Feb 26, 2026 at 6:37 PM Changhui Zhong <czhong@redhat.com> wrote: >>>> >>>> Hello, >>>> >>>> on the ppc64le arch, I hit the issue below with ublksrv on the latest >>>> linux-block/for-next, please help check it, and let me know if you >>>> need any info/test for it. Thanks. >>>> >>>> INFO: HEAD of cloned kernel >>>> commit 37a43fd770f3dcac8f72f3ea909b3e893e2385c9 >>>> Merge: 13cd9b41227a c1dfbd7e71b0 >>>> Author: Jens Axboe <axboe@kernel.dk> >>>> Date: Wed Feb 25 08:37:06 2026 -0700 >>>> >>>> Merge branch 'for-7.1/block' into for-next >>>> >>>> * for-7.1/block: >>>> ublk: report BLK_SPLIT_INTERVAL_CAPABLE >>>> >>>> reproducer: >>>> compile and install https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fublk-org%2Fublksrv.git&data=05%7C02%7Cchristophe.leroy2%40cs-soprasteria.com%7Cf0b0066758be476be95508de75587a73%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639077220067774377%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=ki4yUMx%2FBTANcpfzEoVMdBKsuflIbzhHO2Wqpxtvj5g%3D&reserved=0 >>>> #echo 0 > /proc/sys/kernel/io_uring_disabled >>>> #modprobe ublk_drv >>>> #cd ublksrv >>>> #make test T=null >>>> #make test T=loop >>>> >>>> dmesg log： >>>> Feb 26 00:24:30 ibm-p9z-27-lp26 journal: running null/002 >>>> Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: start ublksrv io >>>> daemon ublksrvd-0 >>>> Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: tid 57923: ublk dev >>>> 0 queue 0 started >>>> Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: tid 57924: ublk dev >>>> 0 queue 1 started >>>> Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083476.4882] platform-linux: do-add-ip6-address[2: >>>> fe80::8448:a3ff:fe51:f102]: failure 13 (Permission denied - ipv6: IPv6 >>>> is disabled on this device) >>>> Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083476.4885] platform-linux: do-add-ip6-address[2: >>>> 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - >>>> ipv6: IPv6 is disabled on this device) >>>> Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083476.4938] l3cfg[0f1985ec14299e62,ifindex=2]: unable to >>>> configure IPv6 route: type unicast fe80::/64 dev 2 metric 1024 mss 0 >>>> rt-src ipv6ll >>>> Feb 26 00:24:38 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083478.4938] ipv6ll[95ab7f3fdbfe643d,ifindex=2]: changed: no IPv6 >>>> link local address to retry after Duplicate Address Detection failures >>>> (back off) >>>> Feb 26 00:24:38 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083478.4943] platform-linux: do-add-ip6-address[2: >>>> 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - >>>> ipv6: IPv6 is disabled on this device) >>>> Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083488.5034] platform-linux: do-add-ip6-address[2: >>>> fe80::8448:a3ff:fe51:f102]: failure 13 (Permission denied - ipv6: IPv6 >>>> is disabled on this device) >>>> Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083488.5037] platform-linux: do-add-ip6-address[2: >>>> 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - >>>> ipv6: IPv6 is disabled on this device) >>>> Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083488.5041] l3cfg[0f1985ec14299e62,ifindex=2]: unable to >>>> configure IPv6 route: type unicast fe80::/64 dev 2 metric 1024 mss 0 >>>> rt-src ipv6ll >>>> Feb 26 00:24:50 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083490.5034] ipv6ll[95ab7f3fdbfe643d,ifindex=2]: changed: no IPv6 >>>> link local address to retry after Duplicate Address Detection failures >>>> (back off) >>>> Feb 26 00:24:50 ibm-p9z-27-lp26 NetworkManager[818]: <warn> >>>> [1772083490.5039] platform-linux: do-add-ip6-address[2: >>>> 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - >>>> ipv6: IPv6 is disabled on this device) >>>> Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: Kernel attempted to read user >>>> page (7fff81210000) - exploit attempt? (uid: 0) >>>> Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: ------------[ cut here ]------------ >>>> Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: Bug: Read fault blocked by KUAP! >>>> Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: WARNING: >>>> arch/powerpc/mm/fault.c:231 at bad_kernel_fault.isra.0+0xc8/0x2c0, >>>> CPU#5: lt-ublk.null/57924 >> >> oops, it shouldn't be related with `ublk: report BLK_SPLIT_INTERVAL_CAPABLE`, >> Perhaps one issue lies in the ppcle64 architecture code. > > Agreed, the "Kernel attempted to read user page" error seems > incorrect. The call trace shows this is in copy_from_iter(), so > reading a user page is expected. I too would be suspicious of the > powerpc copy_from_iter() implementation. Looks similar to: https://lore.kernel.org/all/20260109064917.777587-2-sshegde@linux.ibm.com/ That fix was rejected, more acceptable fix here: https://lore.kernel.org/all/20260217124457.89219-1-sayalip@linux.ibm.com/ Let us know if it fixes the issue for you. Christophe ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [bug report] Bug: Write fault blocked by KUAP! 2026-02-26 18:57 ` Christophe Leroy (CS GROUP) @ 2026-02-28 2:57 ` Changhui Zhong 0 siblings, 0 replies; 4+ messages in thread From: Changhui Zhong @ 2026-02-28 2:57 UTC (permalink / raw) To: Christophe Leroy (CS GROUP) Cc: Caleb Sander Mateos, Ming Lei, Linux Block Devices, linuxppc-dev On Fri, Feb 27, 2026 at 3:05 AM Christophe Leroy (CS GROUP) <chleroy@kernel.org> wrote: > > > > Le 26/02/2026 à 17:59, Caleb Sander Mateos a écrit : > > On Thu, Feb 26, 2026 at 4:44 AM Ming Lei <ming.lei@redhat.com> wrote: > >> > >> On Thu, Feb 26, 2026 at 6:48 PM Ming Lei <ming.lei@redhat.com> wrote: > >>> > >>> Hi Changhui, > >>> > >>> Thanks for the report! > >>> > >>> Loop Caleb Sander Mateos in. > >>> > >>> Thanks, > >>> > >>> On Thu, Feb 26, 2026 at 6:37 PM Changhui Zhong <czhong@redhat.com> wrote: > >>>> > >>>> Hello, > >>>> > >>>> on the ppc64le arch, I hit the issue below with ublksrv on the latest > >>>> linux-block/for-next, please help check it, and let me know if you > >>>> need any info/test for it. Thanks. > >>>> > >>>> INFO: HEAD of cloned kernel > >>>> commit 37a43fd770f3dcac8f72f3ea909b3e893e2385c9 > >>>> Merge: 13cd9b41227a c1dfbd7e71b0 > >>>> Author: Jens Axboe <axboe@kernel.dk> > >>>> Date: Wed Feb 25 08:37:06 2026 -0700 > >>>> > >>>> Merge branch 'for-7.1/block' into for-next > >>>> > >>>> * for-7.1/block: > >>>> ublk: report BLK_SPLIT_INTERVAL_CAPABLE > >>>> > >>>> reproducer: > >>>> compile and install https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fublk-org%2Fublksrv.git&data=05%7C02%7Cchristophe.leroy2%40cs-soprasteria.com%7Cf0b0066758be476be95508de75587a73%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639077220067774377%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=ki4yUMx%2FBTANcpfzEoVMdBKsuflIbzhHO2Wqpxtvj5g%3D&reserved=0 > >>>> #echo 0 > /proc/sys/kernel/io_uring_disabled > >>>> #modprobe ublk_drv > >>>> #cd ublksrv > >>>> #make test T=null > >>>> #make test T=loop > >>>> > >>>> dmesg log： > >>>> Feb 26 00:24:30 ibm-p9z-27-lp26 journal: running null/002 > >>>> Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: start ublksrv io > >>>> daemon ublksrvd-0 > >>>> Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: tid 57923: ublk dev > >>>> 0 queue 0 started > >>>> Feb 26 00:24:30 ibm-p9z-27-lp26 ublksrvd-0[57921]: tid 57924: ublk dev > >>>> 0 queue 1 started > >>>> Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083476.4882] platform-linux: do-add-ip6-address[2: > >>>> fe80::8448:a3ff:fe51:f102]: failure 13 (Permission denied - ipv6: IPv6 > >>>> is disabled on this device) > >>>> Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083476.4885] platform-linux: do-add-ip6-address[2: > >>>> 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > >>>> ipv6: IPv6 is disabled on this device) > >>>> Feb 26 00:24:36 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083476.4938] l3cfg[0f1985ec14299e62,ifindex=2]: unable to > >>>> configure IPv6 route: type unicast fe80::/64 dev 2 metric 1024 mss 0 > >>>> rt-src ipv6ll > >>>> Feb 26 00:24:38 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083478.4938] ipv6ll[95ab7f3fdbfe643d,ifindex=2]: changed: no IPv6 > >>>> link local address to retry after Duplicate Address Detection failures > >>>> (back off) > >>>> Feb 26 00:24:38 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083478.4943] platform-linux: do-add-ip6-address[2: > >>>> 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > >>>> ipv6: IPv6 is disabled on this device) > >>>> Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083488.5034] platform-linux: do-add-ip6-address[2: > >>>> fe80::8448:a3ff:fe51:f102]: failure 13 (Permission denied - ipv6: IPv6 > >>>> is disabled on this device) > >>>> Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083488.5037] platform-linux: do-add-ip6-address[2: > >>>> 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > >>>> ipv6: IPv6 is disabled on this device) > >>>> Feb 26 00:24:48 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083488.5041] l3cfg[0f1985ec14299e62,ifindex=2]: unable to > >>>> configure IPv6 route: type unicast fe80::/64 dev 2 metric 1024 mss 0 > >>>> rt-src ipv6ll > >>>> Feb 26 00:24:50 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083490.5034] ipv6ll[95ab7f3fdbfe643d,ifindex=2]: changed: no IPv6 > >>>> link local address to retry after Duplicate Address Detection failures > >>>> (back off) > >>>> Feb 26 00:24:50 ibm-p9z-27-lp26 NetworkManager[818]: <warn> > >>>> [1772083490.5039] platform-linux: do-add-ip6-address[2: > >>>> 2620:52:9:160c:8448:a3ff:fe51:f102]: failure 13 (Permission denied - > >>>> ipv6: IPv6 is disabled on this device) > >>>> Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: Kernel attempted to read user > >>>> page (7fff81210000) - exploit attempt? (uid: 0) > >>>> Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: ------------[ cut here ]------------ > >>>> Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: Bug: Read fault blocked by KUAP! > >>>> Feb 26 00:24:58 ibm-p9z-27-lp26 kernel: WARNING: > >>>> arch/powerpc/mm/fault.c:231 at bad_kernel_fault.isra.0+0xc8/0x2c0, > >>>> CPU#5: lt-ublk.null/57924 > >> > >> oops, it shouldn't be related with `ublk: report BLK_SPLIT_INTERVAL_CAPABLE`, > >> Perhaps one issue lies in the ppcle64 architecture code. > > > > Agreed, the "Kernel attempted to read user page" error seems > > incorrect. The call trace shows this is in copy_from_iter(), so > > reading a user page is expected. I too would be suspicious of the > > powerpc copy_from_iter() implementation. > > Looks similar to: > > https://lore.kernel.org/all/20260109064917.777587-2-sshegde@linux.ibm.com/ > > That fix was rejected, more acceptable fix here: > > https://lore.kernel.org/all/20260217124457.89219-1-sayalip@linux.ibm.com/ > > Let us know if it fixes the issue for you. > > Christophe > Hi， Christophe confirmed that after applying the patch https://lore.kernel.org/all/20260217124457.89219-1-sayalip@linux.ibm.com/, this issue has not been hit again, the fix works. Thanks, Changhui ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-02-28 6:10 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <CAGVVp+U0EYVX+VbbEHzcYP70zdmOXwAmUvpMYV9y3jBSRFmS6g@mail.gmail.com>
[not found] ` <CAFj5m9L8ahNYFf-tUAZFKAUzkeyqV-Sx94MxC268XJ-hqHPCig@mail.gmail.com>
2026-02-26 12:44 ` [bug report] Bug: Write fault blocked by KUAP! Ming Lei
2026-02-26 16:59 ` Caleb Sander Mateos
2026-02-26 18:57 ` Christophe Leroy (CS GROUP)
2026-02-28 2:57 ` Changhui Zhong
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox