Hi Stefan, > > Jan Palus already reported this NULL pointer dereference on bugzilla > > [1], but i want to make sure this is noticed by the right people. > > > > I've i boot my Raspberry Pi 3 B Plus with multi_v7_defconfig and the > > following config settings: > > > > CONFIG_BPF_SYSCALL=y > > CONFIG_BPF_JIT=y > > CONFIG_BPF_JIT_ALWAYS_ON=y > > CONFIG_BPF_JIT_DEFAULT_ON=y > > CONFIG_BPF_UNPRIV_DEFAULT_OFF=y > > CONFIG_USERMODE_DRIVER=y > > CONFIG_BPF_PRELOAD=y > > CONFIG_BPF_PRELOAD_UMD=m > are you able to see this issue in 5.18.x, too? I'm asking because the > BPF settings comes from your configuration. I've not seen it in a standard boot, is there a simple way to test this, TBH I've never really played with bpf (it's on the todo list) so if there's an easy test I can certainly check. > > > > The kernel (Linux 5.18.3) crashes with a null pointer deference: > > > > [ 5.551587] Unable to handle kernel NULL pointer dereference at > > virtual address 00000048 > > [ 5.564467] [00000048] *pgd=39a12835 > > [ 5.572700] Internal error: Oops: 17 [#1] SMP ARM > > [ 5.581249] Modules linked in: bpf_preload(+) > > [ 5.589400] CPU: 1 PID: 85 Comm: modprobe Not tainted 5.18.3 #1 > > [ 5.597966] usb 1-1.1: new high-speed USB device number 3 using dwc2 > > [ 5.599251] Hardware name: BCM2835 > > [ 5.616839] PC is at mmiocpy+0xc8/0x334 > > [ 5.624534] LR is at copy_from_bpfptr+0x60/0x80 > > [ 5.632973] pc : [<c06e77e8>] lr : [<c03fee50>] psr: 60000013 > > [ 5.643146] sp : f1515b30 ip : f1515b48 fp : f1515b30 > > [ 5.652331] r10: c328e040 r9 : f1515b68 r8 : 00000000 > > [ 5.661506] r7 : c328e040 r6 : 00000002 r5 : 00000048 r4 : 00000002 > > [ 5.672037] r3 : 0000003d r2 : 00000000 r1 : 00000048 r0 : f1515c08 > > [ 5.682572] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM > > Segment none > > [ 5.693670] Control: 10c5383d Table: 023c406a DAC: 00000051 > > [ 5.703426] Register r0 information: 2-page vmalloc region starting > > at 0xf1514000 allocated at kernel_clone+0x98/0x27c > > [ 5.718310] Register r1 information: non-paged memory > > [ 5.727454] Register r2 information: NULL pointer > > [ 5.736205] Register r3 information: non-paged memory > > [ 5.738825] hub 1-1.1:1.0: USB hub found > > [ 5.745334] Register r4 information: non-paged memory > > [ 5.753345] hub 1-1.1:1.0: 3 ports detected > > [ 5.762358] Register r5 information: non-paged memory > > [ 5.762364] Register r6 information: non-paged memory > > [ 5.762368] Register r7 information: slab task_struct start > > c328e040 pointer offset 0 > > [ 5.800440] Register r8 information: NULL pointer > > [ 5.809029] Register r9 information: 2-page vmalloc region starting > > at 0xf1514000 allocated at kernel_clone+0x98/0x27c > > [ 5.823843] Register r10 information: slab task_struct start > > c328e040 pointer offset 0 > > [ 5.835847] Register r11 information: 2-page vmalloc region > > starting at 0xf1514000 allocated at kernel_clone+0x98/0x27c > > [ 5.850796] Register r12 information: 2-page vmalloc region > > starting at 0xf1514000 allocated at kernel_clone+0x98/0x27c > > [ 5.865664] Process modprobe (pid: 85, stack limit = 0x(ptrval)) > > [ 5.867961] usb 1-1.3: new low-speed USB device number 4 using dwc2 > > [ 5.875679] Stack: (0xf1515b30 to 0xf1516000) > > [ 5.894419] 5b20: f1515c08 > > 00000002 00000000 c03fee50 > > [ 5.906750] 5b40: 00000048 c051aa3d 00000000 c0402520 ef80327c > > ef80328c c2001180 f1515c08 > > [ 5.919097] 5b60: c1a45808 00012cc0 00000048 c051aa3d c3022440 > > 00000001 c2ee9898 ffffffff > > [ 5.931435] 5b80: 00000000 f1515bb4 00000000 00000000 c2ee9a48 > > 5beb87ed c22c4c8c 00000000 > > [ 5.943733] 5ba0: 00000001 c328e040 00000000 00012cc0 00000dc0 > > 00000000 f1515f38 c048fb58 > > [ 5.956089] 5bc0: f1515c00 00000000 c328e040 c217c000 4a389946 > > 00000001 00012cc0 ef7ff780 > > [ 5.968456] 5be0: 00000000 4a389946 00000005 00000001 00000001 > > c328e2c0 c1804d8c c036a868 > > [ 5.980852] 5c00: 00000801 ef7ff780 00000000 00000000 00000000 > > 00000000 00000000 00000000 > > [ 5.993238] 5c20: 00000000 00000000 00000000 00000000 00000000 > > 00000000 00000000 00000000 > > [ 6.005643] 5c40: 00000000 00000000 00000000 00000000 00000000 > > 00000000 00000000 00000000 > > [ 6.018026] 5c60: 00000000 00000000 00000000 00000000 00000000 > > 00000000 00000000 00000000 > > [ 6.030371] 5c80: 00000000 00000000 00000000 00000000 00000000 > > 00000000 00000019 5beb87ed > > [ 6.042719] 5ca0: c2004208 000017a8 00000048 c328e040 ffffffff > > 00000000 c328e040 c328e040 > > [ 6.055020] 5cc0: 00000000 c04043ec 00005dd9 7fffffff c2004208 > > 00000048 c051aa3d 5beb87ed > > [ 6.067330] 5ce0: 00005df9 000017a8 c328e040 c328e040 ffffffff > > 00000000 c328e040 0000017b > > [ 6.079612] 5d00: 00000000 bf0031e0 00000002 00000004 000017a8 > > 00000001 00000000 00000000 > > [ 6.091957] 5d20: 00000000 6f6c5f5f 72656461 70616d2e 00000000 > > 00000000 00000000 00000000 > > [ 6.104254] 5d40: 00000000 00000000 00000000 00000000 c328e040 > > c0380594 c1325856 00000001 > > [ 6.116521] 5d60: c23729a0 c051b97c c23729a0 5beb87ed 00000000 > > 00000000 c200423c c1a4a551 > > [ 6.117969] usb 1-1.1.2: new low-speed USB device number 5 using dwc2 > > [ 6.128707] 5d80: c2372a50 00000001 c1325856 00000124 c2372a50 > > c051b97c c2372a50 5beb87ed > > [ 6.128716] 5da0: 00000000 c22d1980 f1515e6c bf00322c ffffffff > > 00000000 c2372a50 00000000 > > [ 6.163743] 5dc0: 00000030 00000000 c2372a50 c0f179f0 c2348280 > > ef87f900 c2001180 c328e040 > > [ 6.176062] 5de0: c04897dc 00000013 c0464698 c22d1980 c22d1980 > > 00000062 00000cc0 c049d584 > > [ 6.188380] 5e00: 00000cc0 c328e040 c22d1980 5beb87ed 00000001 > > 00000cc0 00000062 bf00a05c > > [ 6.200720] 5e20: ffffffff c1a4a9e0 c328e040 0000017b 00000000 > > c0464698 c2348280 5beb87ed > > [ 6.213033] 5e40: 00000002 c328e040 bf007280 5beb87ed c22d1980 > > bf007280 c328e040 c2348280 > > [ 6.225441] 5e60: 00000000 bf00a0e0 00000001 c2348280 bf0040b7 > > bf005860 000017a8 000008a8 > > [ 6.237841] 5e80: 00000000 5beb87ed c328e040 bf00a000 c23481c0 > > 00000000 c1a4a9e0 c0301f30 > > [ 6.250269] 5ea0: c357a3c0 c357a3c0 00000000 00000000 00000000 > > 00000000 c03c17f0 c23481c0 > > [ 6.262591] 5ec0: c2001180 00000cc0 c03c17f0 c049d888 00000cc0 > > 00000000 c23481c0 5beb87ed > > [ 6.274942] 5ee0: 00000000 bf007040 0002d064 5beb87ed bf007040 > > 0002d064 c23481c0 c328e040 > > [ 6.287336] 5f00: c0300324 c03c1810 bf007040 0000008f 00000000 > > 0002d064 00000000 c03c3ce4 > > [ 6.299841] 5f20: f1515f34 7fffffff 00000000 00000002 c353e040 > > f151b000 f151d8cf f151d940 > > [ 6.312151] 5f40: f151b000 00003f1c f151e904 f151e760 f151e25c > > 00005000 00005150 00002884 > > [ 6.324534] 5f60: 00005241 00000000 00000000 00000000 00002874 > > 00000024 00000025 0000001b > > [ 6.336923] 5f80: 00000000 00000017 00000000 5beb87ed 00000000 > > bbbecb00 000417d8 00000000 > > [ 6.349310] 5fa0: 0000017b c03000c0 bbbecb00 000417d8 00000000 > > 0002d064 00000000 0002ec3c > > [ 6.361662] 5fc0: bbbecb00 000417d8 00000000 0000017b 00042ce0 > > 00000000 00042c38 00000000 > > [ 6.374053] 5fe0: be8e3a88 be8e3a78 00022cb8 b6cb3ae0 60000010 > > 00000000 00000000 00000000 > > [ 6.386437] mmiocpy from copy_from_bpfptr+0x60/0x80 > > [ 6.395558] copy_from_bpfptr from __sys_bpf+0x78/0x1d30 > > [ 6.404992] __sys_bpf from bpf_sys_bpf+0x214/0x238 > > [ 6.413982] bpf_sys_bpf from skel_map_create.constprop.0+0x60/0x80 > > [bpf_preload] > > [ 6.425677] skel_map_create.constprop.0 [bpf_preload] from > > bpf_load_and_run.constprop.0+0x2c/0x1f8 [bpf_preload] > > [ 6.440256] bpf_load_and_run.constprop.0 [bpf_preload] from > > load+0xe0/0x1000 [bpf_preload] > > [ 6.452929] load [bpf_preload] from do_one_initcall+0x68/0x170 > > [ 6.463114] do_one_initcall from do_init_module+0x3c/0x1e0 > > [ 6.472955] do_init_module from sys_finit_module+0xc8/0xd4 > > [ 6.482802] sys_finit_module from ret_fast_syscall+0x0/0x54 > > [ 6.492679] Exception stack(0xf1515fa8 to 0xf1515ff0) > > [ 6.501975] 5fa0: bbbecb00 000417d8 00000000 > > 0002d064 00000000 0002ec3c > > [ 6.514476] 5fc0: bbbecb00 000417d8 00000000 0000017b 00042ce0 > > 00000000 00042c38 00000000 > > [ 6.526999] 5fe0: be8e3a88 be8e3a78 00022cb8 b6cb3ae0 > > [ 6.536392] Code: e480e004 e8bd0360 e1b02f82 14d13001 (24d14001) > > [ 6.546878] ---[ end trace 0000000000000000 ]--- > > > > It would be nice to get a hint, how to narrow down or which commit > > might trigger this issue. > > > > [1] - https://bugzilla.kernel.org/show_bug.cgi?id=216105 > >
