Eric Dumazet
037a6cd7aa
ipv6: fix possible race in __fib6_drop_pcpu_from()
...
[ Upstream commit b01e1c030770ff3b4fe37fc7cc6bca03f594133f ]
syzbot found a race in __fib6_drop_pcpu_from() [1]
If compiler reads more than once (*ppcpu_rt),
second read could read NULL, if another cpu clears
the value in rt6_get_pcpu_route().
Add a READ_ONCE() to prevent this race.
Also add rcu_read_lock()/rcu_read_unlock() because
we rely on RCU protection while dereferencing pcpu_rt.
[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1 ] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
CPU: 0 PID: 7543 Comm: kworker/u8:17 Not tainted 6.10.0-rc1-syzkaller-00013-g2bfcfd584ff5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: netns cleanup_net
RIP: 0010:__fib6_drop_pcpu_from.part.0+0x10a/0x370 net/ipv6/ip6_fib.c:984
Code: f8 48 c1 e8 03 80 3c 28 00 0f 85 16 02 00 00 4d 8b 3f 4d 85 ff 74 31 e8 74 a7 fa f7 49 8d bf 90 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 1e 02 00 00 49 8b 87 90 00 00 00 48 8b 0c 24 48
RSP: 0018:ffffc900040df070 EFLAGS: 00010206
RAX: 0000000000000012 RBX: 0000000000000001 RCX: ffffffff89932e16
RDX: ffff888049dd1e00 RSI: ffffffff89932d7c RDI: 0000000000000091
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000001 R11: 0000000000000006 R12: ffff88807fa080b8
R13: fffffbfff1a9a07d R14: ffffed100ff41022 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32c26000 CR3: 000000005d56e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__fib6_drop_pcpu_from net/ipv6/ip6_fib.c:966 [inline]
fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1027 [inline]
fib6_purge_rt+0x7f2/0x9f0 net/ipv6/ip6_fib.c:1038
fib6_del_route net/ipv6/ip6_fib.c:1998 [inline]
fib6_del+0xa70/0x17b0 net/ipv6/ip6_fib.c:2043
fib6_clean_node+0x426/0x5b0 net/ipv6/ip6_fib.c:2205
fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2127
fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2175
fib6_clean_tree+0xd7/0x120 net/ipv6/ip6_fib.c:2255
__fib6_clean_all+0x100/0x2d0 net/ipv6/ip6_fib.c:2271
rt6_sync_down_dev net/ipv6/route.c:4906 [inline]
rt6_disable_ip+0x7ed/0xa00 net/ipv6/route.c:4911
addrconf_ifdown.isra.0+0x117/0x1b40 net/ipv6/addrconf.c:3855
addrconf_notify+0x223/0x19e0 net/ipv6/addrconf.c:3778
notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992
call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
call_netdevice_notifiers net/core/dev.c:2044 [inline]
dev_close_many+0x333/0x6a0 net/core/dev.c:1585
unregister_netdevice_many_notify+0x46d/0x19f0 net/core/dev.c:11193
unregister_netdevice_many net/core/dev.c:11276 [inline]
default_device_exit_batch+0x85b/0xae0 net/core/dev.c:11759
ops_exit_list+0x128/0x180 net/core/net_namespace.c:178
cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640
process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231
process_scheduled_works kernel/workqueue.c:3312 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Fixes: d52d3997f843 ("ipv6: Create percpu rt6_info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20240604193549.981839-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:01 +01:00
Arnd Bergmann
7d04625a9b
ipv6: fib: hide unused 'pn' variable
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[ Upstream commit 74043489fcb5e5ca4074133582b5b8011b67f9e7 ]
When CONFIG_IPV6_SUBTREES is disabled, the only user is hidden, causing
a 'make W=1' warning:
net/ipv6/ip6_fib.c: In function 'fib6_add':
net/ipv6/ip6_fib.c:1388:32: error: variable 'pn' set but not used [-Werror=unused-but-set-variable]
Add another #ifdef around the variable declaration, matching the other
uses in this file.
Fixes: 66729e18df08 ("[IPV6] ROUTE: Make sure we have fn->leaf when adding a node on subtree.")
Link: https://lore.kernel.org/netdev/20240322131746.904943-1-arnd@kernel.org/
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240408074219.3030256-1-arnd@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 11:32:19 +01:00
Kuniyuki Iwashima
66dcf54d25
ipv6: Fix infinite recursion in fib6_dump_done().
...
commit d21d40605bca7bd5fc23ef03d4c1ca1f48bc2cae upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 09:22:47 +01:00
Eric Dumazet
1e354a809f
ipv6: fix potential NULL deref in fib6_add()
...
[ Upstream commit 75475bb51e78a3f54ad2f69380f2a1c985e85f2d ]
If fib6_find_prefix() returns NULL, we should silently fallback
using fib6_null_entry regardless of RT6_DEBUG value.
syzbot reported:
WARNING: CPU: 0 PID: 5477 at net/ipv6/ip6_fib.c:1516 fib6_add+0x310d/0x3fa0 net/ipv6/ip6_fib.c:1516
Modules linked in:
CPU: 0 PID: 5477 Comm: syz-executor.0 Not tainted 6.7.0-rc2-syzkaller-00029-g9b6de136b5f0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
RIP: 0010:fib6_add+0x310d/0x3fa0 net/ipv6/ip6_fib.c:1516
Code: 00 48 8b 54 24 68 e8 42 22 00 00 48 85 c0 74 14 49 89 c6 e8 d5 d3 c2 f7 eb 5d e8 ce d3 c2 f7 e9 ca 00 00 00 e8 c4 d3 c2 f7 90 <0f> 0b 90 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 38 80 3c 01 00
RSP: 0018:ffffc90005067740 EFLAGS: 00010293
RAX: ffffffff89cba5bc RBX: ffffc90005067ab0 RCX: ffff88801a2e9dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90005067980 R08: ffffffff89cbca85 R09: 1ffff110040d4b85
R10: dffffc0000000000 R11: ffffed10040d4b86 R12: 00000000ffffffff
R13: 1ffff110051c3904 R14: ffff8880206a5c00 R15: ffff888028e1c820
FS: 00007f763783c6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f763783bff8 CR3: 000000007f74d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__ip6_ins_rt net/ipv6/route.c:1303 [inline]
ip6_route_add+0x88/0x120 net/ipv6/route.c:3847
ipv6_route_ioctl+0x525/0x7b0 net/ipv6/route.c:4467
inet6_ioctl+0x21a/0x270 net/ipv6/af_inet6.c:575
sock_do_ioctl+0x152/0x460 net/socket.c:1220
sock_ioctl+0x615/0x8c0 net/socket.c:1339
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xf8/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
Fixes: 7bbfe00e0252 ("ipv6: fix general protection fault in fib6_add()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20231129160630.3509216-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 12:11:38 +01:00
Eric Dumazet