On 07/20/2018 02:45 PM, John Paul Adrian Glaubitz wrote: > Running "strace ./tweaklib2" will immediately trigger the crash (see below). > > I have uploaded the test binary and source code to my Debian space: > >> https://people.debian.org/~glaubitz/kernel-crash-test.tar.gz Running as normal user: glaubitz@stadler:~/kernel-crash-test$ ./tweaklib2 Illegal instruction glaubitz@stadler:~/kernel-crash-test$ strace ./tweaklib2 execve("./tweaklib2", ["./tweaklib2"], 0x7feffead590 /* 22 vars */) = 0 brk(NULL) = 0x264000 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) mmap(NULL, 16384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffff800100024000 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "./tls/v9v/libtweaklib1.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "./tls/libtweaklib1.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "./v9v/libtweaklib1.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "./libtweaklib1.so", O_RDONLY|O_CLOEXEC) = 3 read(3, "\177ELF\2\2\1\0\0\0\0\0\0\0\0\0\0\3\0+\0\0\0\1\0\0\0\0\0\0\310\360"..., 832) = 832 fstat64(3, {st_mode=S_IFREG|0755, st_size=1165312, ...}) = 0 getcwd("/home/glaubitz/kernel-crash-test", 128) = 33 mmap(NULL, 1503776, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xffff800100128000 mprotect(0xffff800100188000, 1040384, PROT_NONE) = 0 mmap(0xffff800100286000, 57344, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x5e000) = 0xffff800100286000 mmap(0xffff800100294000, 12832, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xffff800100294000 close(3) = 0 mprotect(0xffff800100286000, 8192, PROT_READ) = 0 mprotect(0x252000, 8192, PROT_READ) = 0 mprotect(0xffff800100122000, 8192, PROT_READ) = 0 getrlimit(RLIMIT_STACK, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0 rt_sigaction(SIGFPE, {sa_handler=0xffff800100180e10, sa_mask=[], sa_flags=SA_SIGINFO}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 0xffff800100134ca8, 8) = 0 rt_sigaction(SIGSEGV, {sa_handler=0xffff800100180e10, sa_mask=[], sa_flags=SA_SIGINFO}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 0xffff800100134ca8, 8) = 0 rt_sigaction(SIGBUS, {sa_handler=0xffff800100180e10, sa_mask=[], sa_flags=SA_SIGINFO}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 0xffff800100134ca8, 8) = 0 rt_sigaction(SIGILL, {sa_handler=0xffff800100180e10, sa_mask=[], sa_flags=SA_SIGINFO}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 0xffff800100134ca8, 8) = 0 ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0 ioctl(2, TCGETS, {B38400 opost isig icanon echo ...}) = 0 ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0 ioctl(2, TCGETS, {B38400 opost isig icanon echo ...}) = 0 readlink("/proc/self/exe", "/home/glaubitz/kernel-crash-test"..., 255) = 42 rt_sigaction(SIGFPE, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, NULL, 0xffff800100134ca8, 8) = 0 rt_sigaction(SIGSEGV, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, NULL, 0xffff800100134ca8, 8) = 0 rt_sigaction(SIGBUS, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, NULL, 0xffff800100134ca8, 8) = 0 rt_sigaction(SIGILL, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, NULL, 0xffff800100134ca8, 8) = 0 And the kernel: [ 147.715770] usercopy: Kernel memory exposure attempt detected from null address (offset 0, size 128)! [ 147.716477] usercopy: Kernel memory exposure attempt detected from null address (offset 0, size 128)! [ 147.717349] usercopy: Kernel memory exposure attempt detected from null address (offset 0, size 128)! [ 147.718276] usercopy: Kernel memory exposure attempt detected from null address (offset 0, size 128)! [ 147.719250] usercopy: Kernel memory exposure attempt detected from null address (offset 0, size 128)! [ 168.727220] INFO: rcu_sched detected stalls on CPUs/tasks: [ 168.727399] 20-...!: (1 GPs behind) idle=ac2/1/4611686018427387906 softirq=2161/2162 fqs=364 [ 168.727499] (detected by 8, t=5252 jiffies, g=1073, c=1072, q=44) [ 168.727759] rcu_sched kthread starved for 4524 jiffies! g1073 c1072 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=16 [ 168.727825] RCU grace-period kthread stack dump: [ 231.869098] INFO: rcu_sched detected stalls on CPUs/tasks: [ 231.869295] 20-...!: (1 GPs behind) idle=ac2/1/4611686018427387906 softirq=2161/2162 fqs=364 [ 231.869399] (detected by 17, t=21038 jiffies, g=1073, c=1072, q=114) [ 231.869758] rcu_sched kthread starved for 20310 jiffies! g1073 c1072 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=16 [ 231.870020] RCU grace-period kthread stack dump: -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer - glaubitz@xxxxxxxxxx `. `' Freie Universitaet Berlin - glaubitz@xxxxxxxxxxxxxxxxxxx `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913 -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
