On Thu, 16 Apr 2020 21:19:10 -0400 Qian Cai <c...@lca.pw> wrote: > OK, reverted the commit, > > c55d7b5e6426 (“powerpc: Remove STRICT_KERNEL_RWX incompatibility with > RELOCATABLE”) > > or set STRICT_KERNEL_RWX=n fixed the crash below and also mentioned in this > thread,
This may be a symptom and not a cure. > > https://lore.kernel.org/lkml/15ac5b0e-a221-4b8c-9039-fa96b8ef7...@lca.pw/ > > [ 148.110969][T13115] LTP: starting chown04_16 > [ 148.255048][T13380] kernel tried to execute exec-protected page > (c0000000016804ac) - exploit attempt? (uid: 0) > [ 148.255099][T13380] BUG: Unable to handle kernel instruction fetch > [ 148.255122][T13380] Faulting instruction address: 0xc0000000016804ac > [ 148.255136][T13380] Oops: Kernel access of bad area, sig: 11 [#1] > [ 148.255157][T13380] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=256 > DEBUG_PAGEALLOC NUMA PowerNV > [ 148.255171][T13380] Modules linked in: loop kvm_hv kvm xfs sd_mod bnx2x > mdio ahci tg3 libahci libphy libata firmware_class dm_mirror dm_region_hash > dm_log dm_mod > [ 148.255213][T13380] CPU: 45 PID: 13380 Comm: chown04_16 Tainted: G > W 5.6.0+ #7 > [ 148.255236][T13380] NIP: c0000000016804ac LR: c00800000fa60408 CTR: > c0000000016804ac > [ 148.255250][T13380] REGS: c0000010a6fafa00 TRAP: 0400 Tainted: G > W (5.6.0+) > [ 148.255281][T13380] MSR: 9000000010009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: > 84000248 XER: 20040000 > [ 148.255310][T13380] CFAR: c00800000fa66534 IRQMASK: 0 > [ 148.255310][T13380] GPR00: c000000000973268 c0000010a6fafc90 > c000000001648200 0000000000000000 > [ 148.255310][T13380] GPR04: c000000d8a22dc00 c0000010a6fafd30 > 00000000b5e98331 ffffffff00012c9f > [ 148.255310][T13380] GPR08: c000000d8a22dc00 0000000000000000 > 0000000000000000 c00000000163c520 > [ 148.255310][T13380] GPR12: c0000000016804ac c000001ffffdad80 > 0000000000000000 0000000000000000 > [ 148.255310][T13380] GPR16: 0000000000000000 0000000000000000 > 0000000000000000 0000000000000000 > [ 148.255310][T13380] GPR20: 0000000000000000 0000000000000000 > 0000000000000000 0000000000000000 > [ 148.255310][T13380] GPR24: 00007fff8f5e2e48 0000000000000000 > c00800000fa6a488 c0000010a6fafd30 > [ 148.255310][T13380] GPR28: 0000000000000000 000000007fffffff > c00800000fa60400 c000000efd0c6780 > [ 148.255494][T13380] NIP [c0000000016804ac] sysctl_net_busy_read+0x0/0x4 The instruction pointer is on sysctl_net_busy_read? Isn't that data and not code? In net/socket.c: #ifdef CONFIG_NET_RX_BUSY_POLL unsigned int sysctl_net_busy_read __read_mostly; unsigned int sysctl_net_busy_poll __read_mostly; #endif -- Steve > [ 148.255516][T13380] LR [c00800000fa60408] find_free_cb+0x8/0x30 [loop] > [ 148.255528][T13380] Call Trace: > [ 148.255538][T13380] [c0000010a6fafc90] [c0000000009732c0] > idr_for_each+0xf0/0x170 (unreliable) > [ 148.255572][T13380] [c0000010a6fafd10] [c00800000fa626c4] > loop_lookup.part.1+0x4c/0xb0 [loop] > [ 148.255597][T13380] [c0000010a6fafd50] [c00800000fa634d8] > loop_control_ioctl+0x120/0x1d0 [loop] > [ 148.255623][T13380] [c0000010a6fafdb0] [c0000000004ddc08] > ksys_ioctl+0xd8/0x130 > [ 148.255636][T13380] [c0000010a6fafe00] [c0000000004ddc88] > sys_ioctl+0x28/0x40 > [ 148.255669][T13380] [c0000010a6fafe20] [c00000000000b378] > system_call+0x5c/0x68 > [ 148.255699][T13380] Instruction dump: > [ 148.255718][T13380] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX > XXXXXXXX XXXXXXXX > [ 148.255744][T13380] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX > XXXXXXXX XXXXXXXX > [ 148.255772][T13380] ---[ end trace a5894a74208c22ec ]--- > [ 148.576663][T13380] > [ 149.576765][T13380] Kernel panic - not syncing: Fatal exception >
