Revision d21d40605bca7bd5fc23ef03d4c1ca1f48bc2cae authored by Kuniyuki Iwashima on 01 April 2024, 21:10:04 UTC, committed by Jakub Kicinski on 03 April 2024, 02:10:57 UTC
syzkaller reported infinite recursive calls of fib6_dump_done() during netlink socket destruction. [1] From the log, syzkaller sent an AF_UNSPEC RTM_GETROUTE message, and then the response was generated. The following recvmmsg() resumed the dump for IPv6, but the first call of inet6_dump_fib() failed at kzalloc() due to the fault injection. [0] 12:01:34 executing program 3: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route(r0, ... snip ...) recvmmsg(r0, ... snip ...) (fail_nth: 8) Here, fib6_dump_done() was set to nlk_sk(sk)->cb.done, and the next call of inet6_dump_fib() set it to nlk_sk(sk)->cb.args[3]. syzkaller stopped receiving the response halfway through, and finally netlink_sock_destruct() called nlk_sk(sk)->cb.done(). fib6_dump_done() calls fib6_dump_end() and nlk_sk(sk)->cb.done() if it is still not NULL. fib6_dump_end() rewrites nlk_sk(sk)->cb.done() by nlk_sk(sk)->cb.args[3], but it has the same function, not NULL, calling itself recursively and hitting the stack guard page. To avoid the issue, let's set the destructor after kzalloc(). [0]: FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 432110 Comm: syz-executor.3 Not tainted 6.8.0-12821-g537c2e91d354-dirty #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:117) should_fail_ex (lib/fault-inject.c:52 lib/fault-inject.c:153) should_failslab (mm/slub.c:3733) kmalloc_trace (mm/slub.c:3748 mm/slub.c:3827 mm/slub.c:3992) inet6_dump_fib (./include/linux/slab.h:628 ./include/linux/slab.h:749 net/ipv6/ip6_fib.c:662) rtnl_dump_all (net/core/rtnetlink.c:4029) netlink_dump (net/netlink/af_netlink.c:2269) netlink_recvmsg (net/netlink/af_netlink.c:1988) ____sys_recvmsg (net/socket.c:1046 net/socket.c:2801) ___sys_recvmsg (net/socket.c:2846) do_recvmmsg (net/socket.c:2943) __x64_sys_recvmmsg (net/socket.c:3041 net/socket.c:3034 net/socket.c:3034) [1]: BUG: TASK stack guard page was hit at 00000000f2fa9af1 (stack is 00000000b7912430..000000009a436beb) stack guard page: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 223719 Comm: kworker/1:3 Not tainted 6.8.0-12821-g537c2e91d354-dirty #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Workqueue: events netlink_sock_destruct_work RIP: 0010:fib6_dump_done (net/ipv6/ip6_fib.c:570) Code: 3c 24 e8 f3 e9 51 fd e9 28 fd ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 41 57 41 56 41 55 41 54 55 48 89 fd <53> 48 8d 5d 60 e8 b6 4d 07 fd 48 89 da 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc9000d980000 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffffffff84405990 RCX: ffffffff844059d3 RDX: ffff8881028e0000 RSI: ffffffff84405ac2 RDI: ffff88810c02f358 RBP: ffff88810c02f358 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000224 R12: 0000000000000000 R13: ffff888007c82c78 R14: ffff888007c82c68 R15: ffff888007c82c68 FS: 0000000000000000(0000) GS:ffff88811b100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc9000d97fff8 CR3: 0000000102309002 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <#DF> </#DF> <TASK> fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1)) fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1)) ... fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1)) fib6_dump_done (net/ipv6/ip6_fib.c:572 (discriminator 1)) netlink_sock_destruct (net/netlink/af_netlink.c:401) __sk_destruct (net/core/sock.c:2177 (discriminator 2)) sk_destruct (net/core/sock.c:2224) __sk_free (net/core/sock.c:2235) sk_free (net/core/sock.c:2246) process_one_work (kernel/workqueue.c:3259) worker_thread (kernel/workqueue.c:3329 kernel/workqueue.c:3416) kthread (kernel/kthread.c:388) ret_from_fork (arch/x86/kernel/process.c:153) ret_from_fork_asm (arch/x86/entry/entry_64.S:256) Modules linked in: Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240401211003.25274-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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checkincludes.pl
#!/usr/bin/env perl
# SPDX-License-Identifier: GPL-2.0
#
# checkincludes: find/remove files included more than once
#
# Copyright abandoned, 2000, Niels Kristian Bech Jensen <nkbj@image.dk>.
# Copyright 2009 Luis R. Rodriguez <mcgrof@gmail.com>
#
# This script checks for duplicate includes. It also has support
# to remove them in place. Note that this will not take into
# consideration macros so you should run this only if you know
# you do have real dups and do not have them under #ifdef's. You
# could also just review the results.
use strict;
sub usage {
print "Usage: checkincludes.pl [-r]\n";
print "By default we just warn of duplicates\n";
print "To remove duplicated includes in place use -r\n";
exit 1;
}
my $remove = 0;
if ($#ARGV < 0) {
usage();
}
if ($#ARGV >= 1) {
if ($ARGV[0] =~ /^-/) {
if ($ARGV[0] eq "-r") {
$remove = 1;
shift;
} else {
usage();
}
}
}
my $dup_counter = 0;
foreach my $file (@ARGV) {
open(my $f, '<', $file)
or die "Cannot open $file: $!.\n";
my %includedfiles = ();
my @file_lines = ();
while (<$f>) {
if (m/^\s*#\s*include\s*[<"](\S*)[>"]/o) {
++$includedfiles{$1};
}
push(@file_lines, $_);
}
close($f);
if (!$remove) {
foreach my $filename (keys %includedfiles) {
if ($includedfiles{$filename} > 1) {
print "$file: $filename is included more than once.\n";
++$dup_counter;
}
}
next;
}
open($f, '>', $file)
or die("Cannot write to $file: $!");
my $dups = 0;
foreach (@file_lines) {
if (m/^\s*#\s*include\s*[<"](\S*)[>"]/o) {
foreach my $filename (keys %includedfiles) {
if ($1 eq $filename) {
if ($includedfiles{$filename} > 1) {
$includedfiles{$filename}--;
$dups++;
++$dup_counter;
} else {
print {$f} $_;
}
}
}
} else {
print {$f} $_;
}
}
if ($dups > 0) {
print "$file: removed $dups duplicate includes\n";
}
close($f);
}
if ($dup_counter == 0) {
print "No duplicate includes found.\n";
}
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