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>
1 parent 5d872c9
export_report.pl
#!/usr/bin/env perl
# SPDX-License-Identifier: GPL-2.0-only
#
# (C) Copyright IBM Corporation 2006.
# Author : Ram Pai (linuxram@us.ibm.com)
#
# Usage: export_report.pl -k Module.symvers [-o report_file ] -f *.mod.c
#
use warnings;
use Getopt::Std;
use strict;
sub numerically {
my $no1 = (split /\s+/, $a)[1];
my $no2 = (split /\s+/, $b)[1];
return $no1 <=> $no2;
}
sub alphabetically {
my ($module1, $value1) = @{$a};
my ($module2, $value2) = @{$b};
return $value1 <=> $value2 || $module2 cmp $module1;
}
sub print_depends_on {
my ($href) = @_;
print "\n";
for my $mod (sort keys %$href) {
my $list = $href->{$mod};
print "\t$mod:\n";
foreach my $sym (sort numerically @{$list}) {
my ($symbol, $no) = split /\s+/, $sym;
printf("\t\t%-25s\n", $symbol);
}
print "\n";
}
print "\n";
print "~"x80 , "\n";
}
sub usage {
print "Usage: @_ -h -k Module.symvers [ -o outputfile ] \n",
"\t-f: treat all the non-option argument as .mod.c files. ",
"Recommend using this as the last option\n",
"\t-h: print detailed help\n",
"\t-k: the path to Module.symvers file. By default uses ",
"the file from the current directory\n",
"\t-o outputfile: output the report to outputfile\n";
exit 0;
}
sub collectcfiles {
my @file;
open my $fh, '< modules.order' or die "cannot open modules.order: $!\n";
while (<$fh>) {
s/\.ko$/.mod.c/;
push (@file, $_)
}
close($fh);
chomp @file;
return @file;
}
my (%SYMBOL, %MODULE, %opt, @allcfiles);
if (not getopts('hk:o:f',\%opt) or defined $opt{'h'}) {
usage($0);
}
if (defined $opt{'f'}) {
@allcfiles = @ARGV;
} else {
@allcfiles = collectcfiles();
}
if (not defined $opt{'k'}) {
$opt{'k'} = "Module.symvers";
}
open (my $module_symvers, '<', $opt{'k'})
or die "Sorry, cannot open $opt{'k'}: $!\n";
if (defined $opt{'o'}) {
open (my $out, '>', $opt{'o'})
or die "Sorry, cannot open $opt{'o'} $!\n";
select $out;
}
#
# collect all the symbols and their attributes from the
# Module.symvers file
#
while ( <$module_symvers> ) {
chomp;
my (undef, $symbol, $module, $gpl, $namespace) = split('\t');
$SYMBOL { $symbol } = [ $module , "0" , $symbol, $gpl];
}
close($module_symvers);
#
# collect the usage count of each symbol.
#
my $modversion_warnings = 0;
foreach my $thismod (@allcfiles) {
my $module;
unless (open ($module, '<', $thismod)) {
warn "Sorry, cannot open $thismod: $!\n";
next;
}
my $state=0;
while ( <$module> ) {
chomp;
if ($state == 0) {
$state = 1 if ($_ =~ /static const struct modversion_info/);
next;
}
if ($state == 1) {
$state = 2 if ($_ =~ /__attribute__\(\(section\("__versions"\)\)\)/);
next;
}
if ($state == 2) {
if ( $_ !~ /0x[0-9a-f]+,/ ) {
next;
}
my $sym = (split /([,"])/,)[4];
my ($module, $value, $symbol, $gpl) = @{$SYMBOL{$sym}};
$SYMBOL{ $sym } = [ $module, $value+1, $symbol, $gpl];
push(@{$MODULE{$thismod}} , $sym);
}
}
if ($state != 2) {
warn "WARNING:$thismod is not built with CONFIG_MODVERSIONS enabled\n";
$modversion_warnings++;
}
close($module);
}
print "\tThis file reports the exported symbols usage patterns by in-tree\n",
"\t\t\t\tmodules\n";
printf("%s\n\n\n","x"x80);
printf("\t\t\t\tINDEX\n\n\n");
printf("SECTION 1: Usage counts of all exported symbols\n");
printf("SECTION 2: List of modules and the exported symbols they use\n");
printf("%s\n\n\n","x"x80);
printf("SECTION 1:\tThe exported symbols and their usage count\n\n");
printf("%-25s\t%-25s\t%-5s\t%-25s\n", "Symbol", "Module", "Usage count",
"export type");
#
# print the list of unused exported symbols
#
foreach my $list (sort alphabetically values(%SYMBOL)) {
my ($module, $value, $symbol, $gpl) = @{$list};
printf("%-25s\t%-25s\t%-10s\t", $symbol, $module, $value);
if (defined $gpl) {
printf("%-25s\n",$gpl);
} else {
printf("\n");
}
}
printf("%s\n\n\n","x"x80);
printf("SECTION 2:\n\tThis section reports export-symbol-usage of in-kernel
modules. Each module lists the modules, and the symbols from that module that
it uses. Each listed symbol reports the number of modules using it\n");
print "\nNOTE: Got $modversion_warnings CONFIG_MODVERSIONS warnings\n\n"
if $modversion_warnings;
print "~"x80 , "\n";
for my $thismod (sort keys %MODULE) {
my $list = $MODULE{$thismod};
my %depends;
$thismod =~ s/\.mod\.c/.ko/;
print "\t\t\t$thismod\n";
foreach my $symbol (@{$list}) {
my ($module, $value, undef, $gpl) = @{$SYMBOL{$symbol}};
push (@{$depends{"$module"}}, "$symbol $value");
}
print_depends_on(\%depends);
}
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