forked from luck/tmp_suning_uos_patched
70f1b0d34b
The usb support for asyncio encoded one of it's values in the wrong field. It should have used si_value but instead used si_addr which is not present in the _rt union member of struct siginfo. The practical result of this is that on a 64bit big endian kernel when delivering a signal to a 32bit process the si_addr field is set to NULL, instead of the expected pointer value. This issue can not be fixed in copy_siginfo_to_user32 as the usb usage of the the _sigfault (aka si_addr) member of the siginfo union when SI_ASYNCIO is set is incompatible with the POSIX and glibc usage of the _rt member of the siginfo union. Therefore replace kill_pid_info_as_cred with kill_pid_usb_asyncio a dedicated function for this one specific case. There are no other users of kill_pid_info_as_cred so this specialization should have no impact on the amount of code in the kernel. Have kill_pid_usb_asyncio take instead of a siginfo_t which is difficult and error prone, 3 arguments, a signal number, an errno value, and an address enconded as a sigval_t. The encoding of the address as a sigval_t allows the code that reads the userspace request for a signal to handle this compat issue along with all of the other compat issues. Add BUILD_BUG_ONs in kernel/signal.c to ensure that we can now place the pointer value at the in si_pid (instead of si_addr). That is the code now verifies that si_pid and si_addr always occur at the same location. Further the code veries that for native structures a value placed in si_pid and spilling into si_uid will appear in userspace in si_addr (on a byte by byte copy of siginfo or a field by field copy of siginfo). The code also verifies that for a 64bit kernel and a 32bit userspace the 32bit pointer will fit in si_pid. I have used the usbsig.c program below written by Alan Stern and slightly tweaked by me to run on a big endian machine to verify the issue exists (on sparc64) and to confirm the patch below fixes the issue. /* usbsig.c -- test USB async signal delivery */ #define _GNU_SOURCE #include <stdio.h> #include <fcntl.h> #include <signal.h> #include <string.h> #include <sys/ioctl.h> #include <unistd.h> #include <endian.h> #include <linux/usb/ch9.h> #include <linux/usbdevice_fs.h> static struct usbdevfs_urb urb; static struct usbdevfs_disconnectsignal ds; static volatile sig_atomic_t done = 0; void urb_handler(int sig, siginfo_t *info , void *ucontext) { printf("Got signal %d, signo %d errno %d code %d addr: %p urb: %p\n", sig, info->si_signo, info->si_errno, info->si_code, info->si_addr, &urb); printf("%s\n", (info->si_addr == &urb) ? "Good" : "Bad"); } void ds_handler(int sig, siginfo_t *info , void *ucontext) { printf("Got signal %d, signo %d errno %d code %d addr: %p ds: %p\n", sig, info->si_signo, info->si_errno, info->si_code, info->si_addr, &ds); printf("%s\n", (info->si_addr == &ds) ? "Good" : "Bad"); done = 1; } int main(int argc, char **argv) { char *devfilename; int fd; int rc; struct sigaction act; struct usb_ctrlrequest *req; void *ptr; char buf[80]; if (argc != 2) { fprintf(stderr, "Usage: usbsig device-file-name\n"); return 1; } devfilename = argv[1]; fd = open(devfilename, O_RDWR); if (fd == -1) { perror("Error opening device file"); return 1; } act.sa_sigaction = urb_handler; sigemptyset(&act.sa_mask); act.sa_flags = SA_SIGINFO; rc = sigaction(SIGUSR1, &act, NULL); if (rc == -1) { perror("Error in sigaction"); return 1; } act.sa_sigaction = ds_handler; sigemptyset(&act.sa_mask); act.sa_flags = SA_SIGINFO; rc = sigaction(SIGUSR2, &act, NULL); if (rc == -1) { perror("Error in sigaction"); return 1; } memset(&urb, 0, sizeof(urb)); urb.type = USBDEVFS_URB_TYPE_CONTROL; urb.endpoint = USB_DIR_IN | 0; urb.buffer = buf; urb.buffer_length = sizeof(buf); urb.signr = SIGUSR1; req = (struct usb_ctrlrequest *) buf; req->bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE; req->bRequest = USB_REQ_GET_DESCRIPTOR; req->wValue = htole16(USB_DT_DEVICE << 8); req->wIndex = htole16(0); req->wLength = htole16(sizeof(buf) - sizeof(*req)); rc = ioctl(fd, USBDEVFS_SUBMITURB, &urb); if (rc == -1) { perror("Error in SUBMITURB ioctl"); return 1; } rc = ioctl(fd, USBDEVFS_REAPURB, &ptr); if (rc == -1) { perror("Error in REAPURB ioctl"); return 1; } memset(&ds, 0, sizeof(ds)); ds.signr = SIGUSR2; ds.context = &ds; rc = ioctl(fd, USBDEVFS_DISCSIGNAL, &ds); if (rc == -1) { perror("Error in DISCSIGNAL ioctl"); return 1; } printf("Waiting for usb disconnect\n"); while (!done) { sleep(1); } close(fd); return 0; } Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-usb@vger.kernel.org Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oneukum@suse.com> Fixes: v2.3.39 Cc: stable@vger.kernel.org Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
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bpf | ||
cgroup | ||
configs | ||
debug | ||
dma | ||
events | ||
gcov | ||
irq | ||
livepatch | ||
locking | ||
power | ||
printk | ||
rcu | ||
sched | ||
time | ||
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acct.c | ||
async.c | ||
audit_fsnotify.c | ||
audit_tree.c | ||
audit_watch.c | ||
audit.c | ||
audit.h | ||
auditfilter.c | ||
auditsc.c | ||
backtracetest.c | ||
bounds.c | ||
capability.c | ||
compat.c | ||
configs.c | ||
context_tracking.c | ||
cpu_pm.c | ||
cpu.c | ||
crash_core.c | ||
crash_dump.c | ||
cred.c | ||
delayacct.c | ||
dma.c | ||
elfcore.c | ||
exec_domain.c | ||
exit.c | ||
extable.c | ||
fail_function.c | ||
fork.c | ||
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gen_ikh_data.sh | ||
groups.c | ||
hung_task.c | ||
iomem.c | ||
irq_work.c | ||
jump_label.c | ||
kallsyms.c | ||
kcmp.c | ||
Kconfig.freezer | ||
Kconfig.hz | ||
Kconfig.locks | ||
Kconfig.preempt | ||
kcov.c | ||
kexec_core.c | ||
kexec_file.c | ||
kexec_internal.h | ||
kexec.c | ||
kheaders.c | ||
kmod.c | ||
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ksysfs.c | ||
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Makefile | ||
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module_signing.c | ||
module-internal.h | ||
module.c | ||
notifier.c | ||
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padata.c | ||
panic.c | ||
params.c | ||
pid_namespace.c | ||
pid.c | ||
profile.c | ||
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range.c | ||
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resource.c | ||
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signal.c | ||
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softirq.c | ||
stackleak.c | ||
stacktrace.c | ||
stop_machine.c | ||
sys_ni.c | ||
sys.c | ||
sysctl_binary.c | ||
sysctl.c | ||
task_work.c | ||
taskstats.c | ||
test_kprobes.c | ||
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tsacct.c | ||
ucount.c | ||
uid16.c | ||
uid16.h | ||
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user_namespace.c | ||
user-return-notifier.c | ||
user.c | ||
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workqueue.c |