Messages in this thread Patch in this message | | | Date | Tue, 30 Nov 2004 10:31:50 -0800 | From | Chris Wright <> | Subject | Re: Buffer overrun in arch/x86_64/sys_ia32.c:sys32_ni_syscall() |
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* Jeremy Fitzhardinge (jeremy@goop.org) wrote: > struct task_struct.comm is defined to be 16 chars, but > arch/x86_64/sys_ia32.c:sys32_ni_syscall() copies it into a static 8 byte > buffer, which will surely cause problems. This patch makes lastcomm[] > the right size, and makes sure it can't be overrun. Since the code also > goes to the effort of getting a local copy of current in "me", we may as > well use it for printing the message.
Looks good, but you missed sys32_vm86_warning.
Signed-off-by: Chris Wright <chrisw@osdl.org>
===== arch/x86_64/ia32/sys_ia32.c 1.74 vs edited ===== --- 1.74/arch/x86_64/ia32/sys_ia32.c 2004-11-02 06:40:37 -08:00 +++ edited/arch/x86_64/ia32/sys_ia32.c 2004-11-30 09:42:26 -08:00 @@ -525,11 +525,12 @@ sys32_waitpid(compat_pid_t pid, unsigned int sys32_ni_syscall(int call) { struct task_struct *me = current; - static char lastcomm[8]; - if (strcmp(lastcomm, me->comm)) { - printk(KERN_INFO "IA32 syscall %d from %s not implemented\n", call, - current->comm); - strcpy(lastcomm, me->comm); + static char lastcomm[sizeof(me->comm)]; + + if (strncmp(lastcomm, me->comm, sizeof(lastcomm))) { + printk(KERN_INFO "IA32 syscall %d from %s not implemented\n", + call, me->comm); + strncpy(lastcomm, me->comm, sizeof(lastcomm)); } return -ENOSYS; } @@ -1125,11 +1126,11 @@ long sys32_fadvise64_64(int fd, __u32 of long sys32_vm86_warning(void) { struct task_struct *me = current; - static char lastcomm[8]; - if (strcmp(lastcomm, me->comm)) { + static char lastcomm[sizeof(me->comm)]; + if (strncmp(lastcomm, me->comm, sizeof(lastcomm))) { printk(KERN_INFO "%s: vm86 mode not supported on 64 bit kernel\n", me->comm); - strcpy(lastcomm, me->comm); + strncpy(lastcomm, me->comm, sizeof(lastcomm)); } return -ENOSYS; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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