On Wed, Dec 27, 2017 at 7:18 PM, syzbot <syzbot+4396883fa8c4f64e0175@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzkaller hit the following crash on > beacbc68ac3e23821a681adb30b45dc55b17488d > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: <syzbot+4396883fa8c4f64e0175@xxxxxxxxxxxxxxxxxxxxxxxxx> > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. +netfilter maintainers Here is cleaned reproducer: // autogenerated by syzkaller (http://github.com/google/syzkaller) #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <netinet/tcp.h> #include <linux/if.h> #include <linux/netfilter_ipv4/ip_tables.h> int main() { int fd; fd = socket(AF_INET, SOCK_STREAM, IPPROTO_IP); struct ipt_replace opt = {}; opt.num_counters = 1; opt.size = -1; setsockopt(fd, SOL_IP, 0x40, &opt, 0x4); return 0; } What happens there is that here: struct xt_table_info *xt_alloc_table_info(unsigned int size) { ... if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages) return NULL; size = -1 and SMP_ALIGN(size) = 0, so this still tries to allocate 4GB+delta bytes. I don't understand why this uses SMP_ALIGN since we add 2 pages on top, it seems that we could just drop SMP_ALIGN and local SMP_ALIGN definition altogether. > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > If you want to test a patch for this bug, please reply with: > #syz test: git://repo/address.git branch > and provide the patch inline or as an attachment. > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > Note: all commands must start from beginning of the line in the email body. > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/001a1143d40c2b55b10561566d26%40google.com. > For more options, visit https://groups.google.com/d/optout. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
