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  1. 02 May, 2024 1 commit
    • Paolo Abeni's avatar
      tipc: fix UAF in error path · 080cbb89
      Paolo Abeni authored 
      Sam Page (sam4k) working with Trend Micro Zero Day Initiative reported
a UAF in the tipc_buf_append() error path:

BUG: KASAN: slab-use-after-free in kfree_skb_list_reason+0x47e/0x4c0
linux/net/core/skbuff.c:1183
Read of size 8 at addr ffff88804d2a7c80 by task poc/8034

CPU: 1 PID: 8034 Comm: poc Not tainted 6.8.2 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.0-debian-1.16.0-5 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack linux/lib/dump_stack.c:88
 dump_stack_lvl+0xd9/0x1b0 linux/lib/dump_stack.c:106
 print_address_description linux/mm/kasan/report.c:377
 print_report+0xc4/0x620 linux/mm/kasan/report.c:488
 kasan_report+0xda/0x110 linux/mm/kasan/report.c:601
 kfree_skb_list_reason+0x47e/0x4c0 linux/net/core/skbuff.c:1183
 skb_release_data+0x5af/0x880 linux/net/core/skbuff.c:1026
 skb_release_all linux/net/core/skbuff.c:1094
 __kfree_skb linux/net/core/skbuff.c:1108
 kfree_skb_reason+0x12d/0x210 linux/net/core/skbuff.c:1144
 kfree_skb linux/./include/linux/skbuff.h:1244
 tipc_buf_append+0x425/0xb50 linux/net/tipc/msg.c:186
 tipc_link_input+0x224/0x7c0 linux/net/tipc/link.c:1324
 tipc_link_rcv+0x76e/0x2d70 linux/net/tipc/link.c:1824
 tipc_rcv+0x45f/0x10f0 linux/net/tipc/node.c:2159
 tipc_udp_recv+0x73b/0x8f0 linux/net/tipc/udp_media.c:390
 udp_queue_rcv_one_skb+0xad2/0x1850 linux/net/ipv4/udp.c:2108
 udp_queue_rcv_skb+0x131/0xb00 linux/net/ipv4/udp.c:2186
 udp_unicast_rcv_skb+0x165/0x3b0 linux/net/ipv4/udp.c:2346
 __udp4_lib_rcv+0x2594/0x3400 linux/net/ipv4/udp.c:2422
 ip_protocol_deliver_rcu+0x30c/0x4e0 linux/net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2e4/0x520 linux/net/ipv4/ip_input.c:233
 NF_HOOK linux/./include/linux/netfilter.h:314
 NF_HOOK linux/./include/linux/netfilter.h:308
 ip_local_deliver+0x18e/0x1f0 linux/net/ipv4/ip_input.c:254
 dst_input linux/./include/net/dst.h:461
 ip_rcv_finish linux/net/ipv4/ip_input.c:449
 NF_HOOK linux/./include/linux/netfilter.h:314
 NF_HOOK linux/./include/linux/netfilter.h:308
 ip_rcv+0x2c5/0x5d0 linux/net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core+0x199/0x1e0 linux/net/core/dev.c:5534
 __netif_receive_skb+0x1f/0x1c0 linux/net/core/dev.c:5648
 process_backlog+0x101/0x6b0 linux/net/core/dev.c:5976
 __napi_poll.constprop.0+0xba/0x550 linux/net/core/dev.c:6576
 napi_poll linux/net/core/dev.c:6645
 net_rx_action+0x95a/0xe90 linux/net/core/dev.c:6781
 __do_softirq+0x21f/0x8e7 linux/kernel/softirq.c:553
 do_softirq linux/kernel/softirq.c:454
 do_softirq+0xb2/0xf0 linux/kernel/softirq.c:441
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x120 linux/kernel/softirq.c:381
 local_bh_enable linux/./include/linux/bottom_half.h:33
 rcu_read_unlock_bh linux/./include/linux/rcupdate.h:851
 __dev_queue_xmit+0x871/0x3ee0 linux/net/core/dev.c:4378
 dev_queue_xmit linux/./include/linux/netdevice.h:3169
 neigh_hh_output linux/./include/net/neighbour.h:526
 neigh_output linux/./include/net/neighbour.h:540
 ip_finish_output2+0x169f/0x2550 linux/net/ipv4/ip_output.c:235
 __ip_finish_output linux/net/ipv4/ip_output.c:313
 __ip_finish_output+0x49e/0x950 linux/net/ipv4/ip_output.c:295
 ip_finish_output+0x31/0x310 linux/net/ipv4/ip_output.c:323
 NF_HOOK_COND linux/./include/linux/netfilter.h:303
 ip_output+0x13b/0x2a0 linux/net/ipv4/ip_output.c:433
 dst_output linux/./include/net/dst.h:451
 ip_local_out linux/net/ipv4/ip_output.c:129
 ip_send_skb+0x3e5/0x560 linux/net/ipv4/ip_output.c:1492
 udp_send_skb+0x73f/0x1530 linux/net/ipv4/udp.c:963
 udp_sendmsg+0x1a36/0x2b40 linux/net/ipv4/udp.c:1250
 inet_sendmsg+0x105/0x140 linux/net/ipv4/af_inet.c:850
 sock_sendmsg_nosec linux/net/socket.c:730
 __sock_sendmsg linux/net/socket.c:745
 __sys_sendto+0x42c/0x4e0 linux/net/socket.c:2191
 __do_sys_sendto linux/net/socket.c:2203
 __se_sys_sendto linux/net/socket.c:2199
 __x64_sys_sendto+0xe0/0x1c0 linux/net/socket.c:2199
 do_syscall_x64 linux/arch/x86/entry/common.c:52
 do_syscall_64+0xd8/0x270 linux/arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6f/0x77 linux/arch/x86/entry/entry_64.S:120
RIP: 0033:0x7f3434974f29
Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48
89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d
01 f0 ff ff 73 01 c3 48 8b 0d 37 8f 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007fff9154f2b8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3434974f29
RDX: 00000000000032c8 RSI: 00007fff9154f300 RDI: 0000000000000003
RBP: 00007fff915532e0 R08: 00007fff91553360 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000212 R12: 000055ed86d261d0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

In the critical scenario, either the relevant skb is freed or its
ownership is transferred into a frag_lists. In both cases, the cleanup
code must not free it again: we need to clear the skb reference earlier.

Fixes: 1149557d ("tipc: eliminate unnecessary linearization of incoming buffers")
Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-23852
Acked-by: default avatarXin Long <lucien.xin@gmail.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/752f1ccf762223d109845365d07f55414058e5a3.1714484273.git.pabeni@redhat.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      080cbb89
  3. 01 May, 2024 8 commits
  5. 29 Apr, 2024 13 commits
  7. 27 Apr, 2024 1 commit
    • Jakub Kicinski's avatar
      Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf · b2ff42c6
      Jakub Kicinski authored 
      Daniel Borkmann says:

====================
pull-request: bpf 2024-04-26

We've added 12 non-merge commits during the last 22 day(s) which contain
a total of 14 files changed, 168 insertions(+), 72 deletions(-).

The main changes are:

1) Fix BPF_PROBE_MEM in verifier and JIT to skip loads from vsyscall page,
   from Puranjay Mohan.

2) Fix a crash in XDP with devmap broadcast redirect when the latter map
   is in process of being torn down, from Toke Høiland-Jørgensen.

3) Fix arm64 and riscv64 BPF JITs to properly clear start time for BPF
   program runtime stats, from Xu Kuohai.

4) Fix a sockmap KCSAN-reported data race in sk_psock_skb_ingress_enqueue,
    from Jason Xing.

5) Fix BPF verifier error message in resolve_pseudo_ldimm64,
   from Anton Protopopov.

6) Fix missing DEBUG_INFO_BTF_MODULES Kconfig menu item,
   from Andrii Nakryiko.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Test PROBE_MEM of VSYSCALL_ADDR on x86-64
  bpf, x86: Fix PROBE_MEM runtime load check
  bpf: verifier: prevent userspace memory access
  xdp: use flags field to disambiguate broadcast redirect
  arm32, bpf: Reimplement sign-extension mov instruction
  riscv, bpf: Fix incorrect runtime stats
  bpf, arm64: Fix incorrect runtime stats
  bpf: Fix a verifier verbose message
  bpf, skmsg: Fix NULL pointer dereference in sk_psock_skb_ingress_enqueue
  MAINTAINERS: bpf: Add Lehui and Puranjay as riscv64 reviewers
  MAINTAINERS: Update email address for Puranjay Mohan
  bpf, kconfig: Fix DEBUG_INFO_BTF_MODULES Kconfig definition
====================

Link: https://lore.kernel.org/r/20240426224248.26197-1-daniel@iogearbox.netSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      b2ff42c6
  9. 26 Apr, 2024 11 commits
    • David Howells's avatar
      Fix a potential infinite loop in extract_user_to_sg() · 6a30653b
      David Howells authored 
      Fix extract_user_to_sg() so that it will break out of the loop if
iov_iter_extract_pages() returns 0 rather than looping around forever.

[Note that I've included two fixes lines as the function got moved to a
different file and renamed]

Fixes: 85dd2c8f ("netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator")
Fixes: f5f82cd1 ("Move netfs_extract_iter_to_sg() to lib/scatterlist.c")
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Steve French <sfrench@samba.org>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: netfs@lists.linux.dev
Link: https://lore.kernel.org/r/1967121.1714034372@warthog.procyon.org.ukSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      6a30653b
    • Alexei Starovoitov's avatar
      Merge branch 'bpf-prevent-userspace-memory-access' · a86538a2
      Alexei Starovoitov authored 
      Puranjay Mohan says:

====================
bpf: prevent userspace memory access

V5: https://lore.kernel.org/bpf/20240324185356.59111-1-puranjay12@gmail.com/
Changes in V6:
- Disable the verifier's instrumentation in x86-64 and update the JIT to
  take care of vsyscall page in addition to userspace addresses.
- Update bpf_testmod to test for vsyscall addresses.

V4: https://lore.kernel.org/bpf/20240321124640.8870-1-puranjay12@gmail.com/
Changes in V5:
- Use TASK_SIZE_MAX + PAGE_SIZE, VSYSCALL_ADDR as userspace boundary in
  x86-64 JIT.
- Added Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>

V3: https://lore.kernel.org/bpf/20240321120842.78983-1-puranjay12@gmail.com/
Changes in V4:
- Disable this feature on architectures that don't define
  CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.
- By doing the above, we don't need anything explicitly for s390x.

V2: https://lore.kernel.org/bpf/20240321101058.68530-1-puranjay12@gmail.com/
Changes in V3:
- Return 0 from bpf_arch_uaddress_limit() in disabled case because it
  returns u64.
- Modify the check in verifier to no do instrumentation when uaddress_limit
  is 0.

V1: https://lore.kernel.org/bpf/20240320105436.4781-1-puranjay12@gmail.com/
Changes in V2:
- Disable this feature on s390x.

With BPF_PROBE_MEM, BPF allows de-referencing an untrusted pointer. To
thwart invalid memory accesses, the JITs add an exception table entry for
all such accesses. But in case the src_reg + offset is a userspace address,
the BPF program might read that memory if the user has mapped it.

x86-64 JIT already instruments the BPF_PROBE_MEM based loads with checks to
skip loads from userspace addresses, but is doesn't check for vsyscall page
because it falls in the kernel address space but is considered a userspace
page. The second patch in this series fixes the x86-64 JIT to also skip
loads from the vsyscall page. The last patch updates the bpf_testmod so
this address can be checked as part of the selftests.

Other architectures don't have the complexity of the vsyscall address and
just need to skip loads from the userspace. To make this more scalable and
robust, the verifier is updated in the first patch to instrument
BPF_PROBE_MEM to skip loads from the userspace addresses.
====================

Link: https://lore.kernel.org/r/20240424100210.11982-1-puranjay@kernel.orgSigned-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      a86538a2
    • Puranjay Mohan's avatar
      selftests/bpf: Test PROBE_MEM of VSYSCALL_ADDR on x86-64 · 7cd6750d
      Puranjay Mohan authored 
      The vsyscall is a legacy API for fast execution of system calls. It maps
a page at address VSYSCALL_ADDR into the userspace program. This address
is in the top 10MB of the address space:

ffffffffff600000 - ffffffffff600fff |    4 kB | legacy vsyscall ABI

The last commit fixes the x86-64 BPF JIT to skip accessing addresses in
this memory region. Add this address to bpf_testmod_return_ptr() so we
can make sure that it is fixed.

After this change and without the previous commit, subprogs_extable
selftest will crash the kernel.
Signed-off-by: default avatarPuranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20240424100210.11982-4-puranjay@kernel.orgSigned-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      7cd6750d
    • Puranjay Mohan's avatar
      bpf, x86: Fix PROBE_MEM runtime load check · b599d7d2
      Puranjay Mohan authored 
      When a load is marked PROBE_MEM - e.g. due to PTR_UNTRUSTED access - the
address being loaded from is not necessarily valid. The BPF jit sets up
exception handlers for each such load which catch page faults and 0 out
the destination register.

If the address for the load is outside kernel address space, the load
will escape the exception handling and crash the kernel. To prevent this
from happening, the emits some instruction to verify that addr is > end
of userspace addresses.

x86 has a legacy vsyscall ABI where a page at address 0xffffffffff600000
is mapped with user accessible permissions. The addresses in this page
are considered userspace addresses by the fault handler. Therefore, a
BPF program accessing this page will crash the kernel.

This patch fixes the runtime checks to also check that the PROBE_MEM
address is below VSYSCALL_ADDR.

Example BPF program:

 SEC("fentry/tcp_v4_connect")
 int BPF_PROG(fentry_tcp_v4_connect, struct sock *sk)
 {
	*(volatile unsigned long *)&sk->sk_tsq_flags;
	return 0;
 }

BPF Assembly:

 0: (79) r1 = *(u64 *)(r1 +0)
 1: (79) r1 = *(u64 *)(r1 +344)
 2: (b7) r0 = 0
 3: (95) exit

			       x86-64 JIT
			       ==========

            BEFORE                                    AFTER
	    ------                                    -----

 0:   nopl   0x0(%rax,%rax,1)             0:   nopl   0x0(%rax,%rax,1)
 5:   xchg   %ax,%ax                      5:   xchg   %ax,%ax
 7:   push   %rbp                         7:   push   %rbp
 8:   mov    %rsp,%rbp                    8:   mov    %rsp,%rbp
 b:   mov    0x0(%rdi),%rdi               b:   mov    0x0(%rdi),%rdi
-------------------------------------------------------------------------------
 f:   movabs $0x100000000000000,%r11      f:   movabs $0xffffffffff600000,%r10
19:   add    $0x2a0,%rdi                 19:   mov    %rdi,%r11
20:   cmp    %r11,%rdi                   1c:   add    $0x2a0,%r11
23:   jae    0x0000000000000029          23:   sub    %r10,%r11
25:   xor    %edi,%edi                   26:   movabs $0x100000000a00000,%r10
27:   jmp    0x000000000000002d          30:   cmp    %r10,%r11
29:   mov    0x0(%rdi),%rdi              33:   ja     0x0000000000000039
--------------------------------\        35:   xor    %edi,%edi
2d:   xor    %eax,%eax           \       37:   jmp    0x0000000000000040
2f:   leave                       \      39:   mov    0x2a0(%rdi),%rdi
30:   ret                          \--------------------------------------------
                                         40:   xor    %eax,%eax
                                         42:   leave
                                         43:   ret
Signed-off-by: default avatarPuranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20240424100210.11982-3-puranjay@kernel.orgSigned-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      b599d7d2
    • Puranjay Mohan's avatar
      bpf: verifier: prevent userspace memory access · 66e13b61
      Puranjay Mohan authored 
      With BPF_PROBE_MEM, BPF allows de-referencing an untrusted pointer. To
thwart invalid memory accesses, the JITs add an exception table entry
for all such accesses. But in case the src_reg + offset is a userspace
address, the BPF program might read that memory if the user has
mapped it.

Make the verifier add guard instructions around such memory accesses and
skip the load if the address falls into the userspace region.

The JITs need to implement bpf_arch_uaddress_limit() to define where
the userspace addresses end for that architecture or TASK_SIZE is taken
as default.

The implementation is as follows:

REG_AX =  SRC_REG
if(offset)
	REG_AX += offset;
REG_AX >>= 32;
if (REG_AX <= (uaddress_limit >> 32))
	DST_REG = 0;
else
	DST_REG = *(size *)(SRC_REG + offset);

Comparing just the upper 32 bits of the load address with the upper
32 bits of uaddress_limit implies that the values are being aligned down
to a 4GB boundary before comparison.

The above means that all loads with address <= uaddress_limit + 4GB are
skipped. This is acceptable because there is a large hole (much larger
than 4GB) between userspace and kernel space memory, therefore a
correctly functioning BPF program should not access this 4GB memory
above the userspace.

Let's analyze what this patch does to the following fentry program
dereferencing an untrusted pointer:

  SEC("fentry/tcp_v4_connect")
  int BPF_PROG(fentry_tcp_v4_connect, struct sock *sk)
  {
                *(volatile long *)sk;
                return 0;
  }

    BPF Program before              |           BPF Program after
    ------------------              |           -----------------

  0: (79) r1 = *(u64 *)(r1 +0)          0: (79) r1 = *(u64 *)(r1 +0)
  -----------------------------------------------------------------------
  1: (79) r1 = *(u64 *)(r1 +0) --\      1: (bf) r11 = r1
  ----------------------------\   \     2: (77) r11 >>= 32
  2: (b7) r0 = 0               \   \    3: (b5) if r11 <= 0x8000 goto pc+2
  3: (95) exit                  \   \-> 4: (79) r1 = *(u64 *)(r1 +0)
                                 \      5: (05) goto pc+1
                                  \     6: (b7) r1 = 0
                                   \--------------------------------------
                                        7: (b7) r0 = 0
                                        8: (95) exit

As you can see from above, in the best case (off=0), 5 extra instructions
are emitted.

Now, we analyze the same program after it has gone through the JITs of
ARM64 and RISC-V architectures. We follow the single load instruction
that has the untrusted pointer and see what instrumentation has been
added around it.

                                x86-64 JIT
                                ==========
     JIT's Instrumentation
          (upstream)
     ---------------------

   0:   nopl   0x0(%rax,%rax,1)
   5:   xchg   %ax,%ax
   7:   push   %rbp
   8:   mov    %rsp,%rbp
   b:   mov    0x0(%rdi),%rdi
  ---------------------------------
   f:   movabs $0x800000000000,%r11
  19:   cmp    %r11,%rdi
  1c:   jb     0x000000000000002a
  1e:   mov    %rdi,%r11
  21:   add    $0x0,%r11
  28:   jae    0x000000000000002e
  2a:   xor    %edi,%edi
  2c:   jmp    0x0000000000000032
  2e:   mov    0x0(%rdi),%rdi
  ---------------------------------
  32:   xor    %eax,%eax
  34:   leave
  35:   ret

The x86-64 JIT already emits some instructions to protect against user
memory access. This patch doesn't make any changes for the x86-64 JIT.

                                  ARM64 JIT
                                  =========

        No Intrumentation                       Verifier's Instrumentation
           (upstream)                                  (This patch)
        -----------------                       --------------------------

   0:   add     x9, x30, #0x0                0:   add     x9, x30, #0x0
   4:   nop                                  4:   nop
   8:   paciasp                              8:   paciasp
   c:   stp     x29, x30, [sp, #-16]!        c:   stp     x29, x30, [sp, #-16]!
  10:   mov     x29, sp                     10:   mov     x29, sp
  14:   stp     x19, x20, [sp, #-16]!       14:   stp     x19, x20, [sp, #-16]!
  18:   stp     x21, x22, [sp, #-16]!       18:   stp     x21, x22, [sp, #-16]!
  1c:   stp     x25, x26, [sp, #-16]!       1c:   stp     x25, x26, [sp, #-16]!
  20:   stp     x27, x28, [sp, #-16]!       20:   stp     x27, x28, [sp, #-16]!
  24:   mov     x25, sp                     24:   mov     x25, sp
  28:   mov     x26, #0x0                   28:   mov     x26, #0x0
  2c:   sub     x27, x25, #0x0              2c:   sub     x27, x25, #0x0
  30:   sub     sp, sp, #0x0                30:   sub     sp, sp, #0x0
  34:   ldr     x0, [x0]                    34:   ldr     x0, [x0]
--------------------------------------------------------------------------------
  38:   ldr     x0, [x0] ----------\        38:   add     x9, x0, #0x0
-----------------------------------\\       3c:   lsr     x9, x9, #32
  3c:   mov     x7, #0x0            \\      40:   cmp     x9, #0x10, lsl #12
  40:   mov     sp, sp               \\     44:   b.ls    0x0000000000000050
  44:   ldp     x27, x28, [sp], #16   \\--> 48:   ldr     x0, [x0]
  48:   ldp     x25, x26, [sp], #16    \    4c:   b       0x0000000000000054
  4c:   ldp     x21, x22, [sp], #16     \   50:   mov     x0, #0x0
  50:   ldp     x19, x20, [sp], #16      \---------------------------------------
  54:   ldp     x29, x30, [sp], #16         54:   mov     x7, #0x0
  58:   add     x0, x7, #0x0                58:   mov     sp, sp
  5c:   autiasp                             5c:   ldp     x27, x28, [sp], #16
  60:   ret                                 60:   ldp     x25, x26, [sp], #16
  64:   nop                                 64:   ldp     x21, x22, [sp], #16
  68:   ldr     x10, 0x0000000000000070     68:   ldp     x19, x20, [sp], #16
  6c:   br      x10                         6c:   ldp     x29, x30, [sp], #16
                                            70:   add     x0, x7, #0x0
                                            74:   autiasp
                                            78:   ret
                                            7c:   nop
                                            80:   ldr     x10, 0x0000000000000088
                                            84:   br      x10

There are 6 extra instructions added in ARM64 in the best case. This will
become 7 in the worst case (off != 0).

                           RISC-V JIT (RISCV_ISA_C Disabled)
                           ==========

        No Intrumentation           Verifier's Instrumentation
           (upstream)                      (This patch)
        -----------------           --------------------------

   0:   nop                            0:   nop
   4:   nop                            4:   nop
   8:   li      a6, 33                 8:   li      a6, 33
   c:   addi    sp, sp, -16            c:   addi    sp, sp, -16
  10:   sd      s0, 8(sp)             10:   sd      s0, 8(sp)
  14:   addi    s0, sp, 16            14:   addi    s0, sp, 16
  18:   ld      a0, 0(a0)             18:   ld      a0, 0(a0)
---------------------------------------------------------------
  1c:   ld      a0, 0(a0) --\         1c:   mv      t0, a0
--------------------------\  \        20:   srli    t0, t0, 32
  20:   li      a5, 0      \  \       24:   lui     t1, 4096
  24:   ld      s0, 8(sp)   \  \      28:   sext.w  t1, t1
  28:   addi    sp, sp, 16   \  \     2c:   bgeu    t1, t0, 12
  2c:   sext.w  a0, a5        \  \--> 30:   ld      a0, 0(a0)
  30:   ret                    \      34:   j       8
                                \     38:   li      a0, 0
                                 \------------------------------
                                      3c:   li      a5, 0
                                      40:   ld      s0, 8(sp)
                                      44:   addi    sp, sp, 16
                                      48:   sext.w  a0, a5
                                      4c:   ret

There are 7 extra instructions added in RISC-V.

Fixes: 80083428 ("bpf, arm64: Add BPF exception tables")
Reported-by: default avatarBreno Leitao <leitao@debian.org>
Suggested-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarIlya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: default avatarPuranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20240424100210.11982-2-puranjay@kernel.orgSigned-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      66e13b61
    • David Bauer's avatar
      net l2tp: drop flow hash on forward · 42f853b4
      David Bauer authored 
      Drop the flow-hash of the skb when forwarding to the L2TP netdev.

This avoids the L2TP qdisc from using the flow-hash from the outer
packet, which is identical for every flow within the tunnel.

This does not affect every platform but is specific for the ethernet
driver. It depends on the platform including L4 information in the
flow-hash.

One such example is the Mediatek Filogic MT798x family of networking
processors.

Fixes: d9e31d17 ("l2tp: Add L2TP ethernet pseudowire support")
Acked-by: default avatarJames Chapman <jchapman@katalix.com>
Signed-off-by: default avatarDavid Bauer <mail@david-bauer.net>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240424171110.13701-1-mail@david-bauer.netSigned-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
      42f853b4
    • Kuniyuki Iwashima's avatar
      nsh: Restore skb->{protocol,data,mac_header} for outer header in nsh_gso_segment(). · 4b911a96
      Kuniyuki Iwashima authored 
      syzbot triggered various splats (see [0] and links) by a crafted GSO
packet of VIRTIO_NET_HDR_GSO_UDP layering the following protocols:

  ETH_P_8021AD + ETH_P_NSH + ETH_P_IPV6 + IPPROTO_UDP

NSH can encapsulate IPv4, IPv6, Ethernet, NSH, and MPLS.  As the inner
protocol can be Ethernet, NSH GSO handler, nsh_gso_segment(), calls
skb_mac_gso_segment() to invoke inner protocol GSO handlers.

nsh_gso_segment() does the following for the original skb before
calling skb_mac_gso_segment()

  1. reset skb->network_header
  2. save the original skb->{mac_heaeder,mac_len} in a local variable
  3. pull the NSH header
  4. resets skb->mac_header
  5. set up skb->mac_len and skb->protocol for the inner protocol.

and does the following for the segmented skb

  6. set ntohs(ETH_P_NSH) to skb->protocol
  7. push the NSH header
  8. restore skb->mac_header
  9. set skb->mac_header + mac_len to skb->network_header
 10. restore skb->mac_len

There are two problems in 6-7 and 8-9.

  (a)
  After 6 & 7, skb->data points to the NSH header, so the outer header
  (ETH_P_8021AD in this case) is stripped when skb is sent out of netdev.

  Also, if NSH is encapsulated by NSH + Ethernet (so NSH-Ethernet-NSH),
  skb_pull() in the first nsh_gso_segment() will make skb->data point
  to the middle of the outer NSH or Ethernet header because the Ethernet
  header is not pulled by the second nsh_gso_segment().

  (b)
  While restoring skb->{mac_header,network_header} in 8 & 9,
  nsh_gso_segment() does not assume that the data in the linear
  buffer is shifted.

  However, udp6_ufo_fragment() could shift the data and change
  skb->mac_header accordingly as demonstrated by syzbot.

  If this happens, even the restored skb->mac_header points to
  the middle of the outer header.

It seems nsh_gso_segment() has never worked with outer headers so far.

At the end of nsh_gso_segment(), the outer header must be restored for
the segmented skb, instead of the NSH header.

To do that, let's calculate the outer header position relatively from
the inner header and set skb->{data,mac_header,protocol} properly.

[0]:
BUG: KMSAN: uninit-value in ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:524 [inline]
BUG: KMSAN: uninit-value in ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline]
BUG: KMSAN: uninit-value in ipvlan_queue_xmit+0xf44/0x16b0 drivers/net/ipvlan/ipvlan_core.c:668
 ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:524 [inline]
 ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline]
 ipvlan_queue_xmit+0xf44/0x16b0 drivers/net/ipvlan/ipvlan_core.c:668
 ipvlan_start_xmit+0x5c/0x1a0 drivers/net/ipvlan/ipvlan_main.c:222
 __netdev_start_xmit include/linux/netdevice.h:4989 [inline]
 netdev_start_xmit include/linux/netdevice.h:5003 [inline]
 xmit_one net/core/dev.c:3547 [inline]
 dev_hard_start_xmit+0x244/0xa10 net/core/dev.c:3563
 __dev_queue_xmit+0x33ed/0x51c0 net/core/dev.c:4351
 dev_queue_xmit include/linux/netdevice.h:3171 [inline]
 packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3081 [inline]
 packet_sendmsg+0x8aef/0x9f10 net/packet/af_packet.c:3113
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x735/0xa10 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:3819 [inline]
 slab_alloc_node mm/slub.c:3860 [inline]
 __do_kmalloc_node mm/slub.c:3980 [inline]
 __kmalloc_node_track_caller+0x705/0x1000 mm/slub.c:4001
 kmalloc_reserve+0x249/0x4a0 net/core/skbuff.c:582
 __alloc_skb+0x352/0x790 net/core/skbuff.c:651
 skb_segment+0x20aa/0x7080 net/core/skbuff.c:4647
 udp6_ufo_fragment+0xcab/0x1150 net/ipv6/udp_offload.c:109
 ipv6_gso_segment+0x14be/0x2ca0 net/ipv6/ip6_offload.c:152
 skb_mac_gso_segment+0x3e8/0x760 net/core/gso.c:53
 nsh_gso_segment+0x6f4/0xf70 net/nsh/nsh.c:108
 skb_mac_gso_segment+0x3e8/0x760 net/core/gso.c:53
 __skb_gso_segment+0x4b0/0x730 net/core/gso.c:124
 skb_gso_segment include/net/gso.h:83 [inline]
 validate_xmit_skb+0x107f/0x1930 net/core/dev.c:3628
 __dev_queue_xmit+0x1f28/0x51c0 net/core/dev.c:4343
 dev_queue_xmit include/linux/netdevice.h:3171 [inline]
 packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3081 [inline]
 packet_sendmsg+0x8aef/0x9f10 net/packet/af_packet.c:3113
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x735/0xa10 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 1 PID: 5101 Comm: syz-executor421 Not tainted 6.8.0-rc5-syzkaller-00297-gf2e367d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024

Fixes: c411ed85 ("nsh: add GSO support")
Reported-and-tested-by: syzbot+42a0dc856239de4de60e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=42a0dc856239de4de60e
Reported-and-tested-by: syzbot+c298c9f0e46a3c86332b@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c298c9f0e46a3c86332b
Link: https://lore.kernel.org/netdev/20240415222041.18537-1-kuniyu@amazon.com/Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240424023549.21862-1-kuniyu@amazon.comSigned-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
      4b911a96
    • Jakub Kicinski's avatar
      Merge branch 'ensure-the-copied-buf-is-nul-terminated' · a5b1051a
      Jakub Kicinski authored 
      Bui Quang Minh says:

====================
Ensure the copied buf is NUL terminated (part)

I found that some drivers contains an out-of-bound read pattern like this

	kern_buf = memdup_user(user_buf, count);
	...
	sscanf(kern_buf, ...);

The sscanf can be replaced by some other string-related functions. This
pattern can lead to out-of-bound read of kern_buf in string-related
functions.

This series fix the above issue by replacing memdup_user with
memdup_user_nul.

v1: https://lore.kernel.org/r/20240422-fix-oob-read-v1-0-e02854c30174@gmail.com
====================

Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-0-f1f1b53a10f4@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      a5b1051a
    • Bui Quang Minh's avatar
      octeontx2-af: avoid off-by-one read from userspace · f299ee70
      Bui Quang Minh authored 
      We try to access count + 1 byte from userspace with memdup_user(buffer,
count + 1). However, the userspace only provides buffer of count bytes and
only these count bytes are verified to be okay to access. To ensure the
copied buffer is NUL terminated, we use memdup_user_nul instead.

Fixes: 3a2eb515 ("octeontx2-af: Fix an off by one in rvu_dbg_qsize_write()")
Signed-off-by: default avatarBui Quang Minh <minhquangbui99@gmail.com>
Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-6-f1f1b53a10f4@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      f299ee70
    • Bui Quang Minh's avatar
      bna: ensure the copied buf is NUL terminated · 8c34096c
      Bui Quang Minh authored 
      Currently, we allocate a nbytes-sized kernel buffer and copy nbytes from
userspace to that buffer. Later, we use sscanf on this buffer but we don't
ensure that the string is terminated inside the buffer, this can lead to
OOB read when using sscanf. Fix this issue by using memdup_user_nul
instead of memdup_user.

Fixes: 7afc5dbd ("bna: Add debugfs interface.")
Signed-off-by: default avatarBui Quang Minh <minhquangbui99@gmail.com>
Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-2-f1f1b53a10f4@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      8c34096c
    • Bui Quang Minh's avatar
      ice: ensure the copied buf is NUL terminated · 666854ea
      Bui Quang Minh authored 
      Currently, we allocate a count-sized kernel buffer and copy count bytes
from userspace to that buffer. Later, we use sscanf on this buffer but we
don't ensure that the string is terminated inside the buffer, this can lead
to OOB read when using sscanf. Fix this issue by using memdup_user_nul
instead of memdup_user.

Fixes: 96a9a934 ("ice: configure FW logging")
Fixes: 73671c31 ("ice: enable FW logging")
Reviewed-by: default avatarPrzemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: default avatarBui Quang Minh <minhquangbui99@gmail.com>
Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-1-f1f1b53a10f4@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      666854ea
  11. 25 Apr, 2024 6 commits
    • Linus Torvalds's avatar
      Merge tag 'net-6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net · 52afb15e
      Linus Torvalds authored 
      Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter, wireless and bluetooth.

  Nothing major, regression fixes are mostly in drivers, two more of
  those are flowing towards us thru various trees. I wish some of the
  changes went into -rc5, we'll try to keep an eye on frequency of PRs
  from sub-trees.

  Also disproportional number of fixes for bugs added in v6.4, strange
  coincidence.

  Current release - regressions:

   - igc: fix LED-related deadlock on driver unbind

   - wifi: mac80211: small fixes to recent clean up of the connection
     process

   - Revert "wifi: iwlwifi: bump FW API to 90 for BZ/SC devices", kernel
     doesn't have all the code to deal with that version, yet

   - Bluetooth:
       - set power_ctrl_enabled on NULL returned by gpiod_get_optional()
       - qca: fix invalid device address check, again

   - eth: ravb: fix registered interrupt names

  Current release - new code bugs:

   - wifi: mac80211: check EHT/TTLM action frame length

  Previous releases - regressions:

   - fix sk_memory_allocated_{add|sub} for architectures where
     __this_cpu_{add|sub}* are not IRQ-safe

   - dsa: mv88e6xx: fix link setup for 88E6250

  Previous releases - always broken:

   - ip: validate dev returned from __in_dev_get_rcu(), prevent possible
     null-derefs in a few places

   - switch number of for_each_rcu() loops using call_rcu() on the
     iterator to for_each_safe()

   - macsec: fix isolation of broadcast traffic in presence of offload

   - vxlan: drop packets from invalid source address

   - eth: mlxsw: trap and ACL programming fixes

   - eth: bnxt: PCIe error recovery fixes, fix counting dropped packets

   - Bluetooth:
       - lots of fixes for the command submission rework from v6.4
       - qca: fix NULL-deref on non-serdev suspend

  Misc:

   - tools: ynl: don't ignore errors in NLMSG_DONE messages"

* tag 'net-6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (88 commits)
  af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc().
  net: b44: set pause params only when interface is up
  tls: fix lockless read of strp->msg_ready in ->poll
  dpll: fix dpll_pin_on_pin_register() for multiple parent pins
  net: ravb: Fix registered interrupt names
  octeontx2-af: fix the double free in rvu_npc_freemem()
  net: ethernet: ti: am65-cpts: Fix PTPv1 message type on TX packets
  ice: fix LAG and VF lock dependency in ice_reset_vf()
  iavf: Fix TC config comparison with existing adapter TC config
  i40e: Report MFS in decimal base instead of hex
  i40e: Do not use WQ_MEM_RECLAIM flag for workqueue
  net: ti: icssg-prueth: Fix signedness bug in prueth_init_rx_chns()
  net/mlx5e: Advertise mlx5 ethernet driver updates sk_buff md_dst for MACsec
  macsec: Detect if Rx skb is macsec-related for offloading devices that update md_dst
  ethernet: Add helper for assigning packet type when dest address does not match device address
  macsec: Enable devices to advertise whether they update sk_buff md_dst during offloads
  net: phy: dp83869: Fix MII mode failure
  netfilter: nf_tables: honor table dormant flag from netdev release event path
  eth: bnxt: fix counting packets discarded due to OOM and netpoll
  igc: Fix LED-related deadlock on driver unbind
  ...
      52afb15e
    • Linus Torvalds's avatar
      Merge tag 'nfsd-6.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux · e33c4963
      Linus Torvalds authored 
      Pull nfsd fixes from Chuck Lever:

 - Revert some backchannel fixes that went into v6.9-rc

* tag 'nfsd-6.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  Revert "NFSD: Convert the callback workqueue to use delayed_work"
  Revert "NFSD: Reschedule CB operations when backchannel rpc_clnt is shut down"
      e33c4963
    • Linus Torvalds's avatar
      Merge tag 'for-linus-2024042501' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid · f9e02329
      Linus Torvalds authored 
      Pull HID fixes from Benjamin Tissoires:

 - A couple of i2c-hid fixes (Kenny Levinsen & Nam Cao)

 - A config issue with mcp-2221 when CONFIG_IIO is not enabled
   (Abdelrahman Morsy)

 - A dev_err fix in intel-ish-hid (Zhang Lixu)

 - A couple of mouse fixes for both nintendo and Logitech-dj (Nuno
   Pereira and Yaraslau Furman)

 - I'm changing my main kernel email address as it's way simpler for me
   than the Red Hat one (Benjamin Tissoires)

* tag 'for-linus-2024042501' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
  HID: mcp-2221: cancel delayed_work only when CONFIG_IIO is enabled
  HID: logitech-dj: allow mice to use all types of reports
  HID: i2c-hid: Revert to await reset ACK before reading report descriptor
  HID: nintendo: Fix N64 controller being identified as mouse
  MAINTAINERS: update Benjamin's email address
  HID: intel-ish-hid: ipc: Fix dev_err usage with uninitialized dev->devc
  HID: i2c-hid: remove I2C_HID_READ_PENDING flag to prevent lock-up
      f9e02329
    • Jakub Kicinski's avatar
      Merge tag 'nf-24-04-25' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf · e8baa63f
      Jakub Kicinski authored 
      Pablo Neira Ayuso says:

====================
Netfilter/IPVS fixes for net

The following patchset contains two Netfilter/IPVS fixes for net:

Patch #1 fixes SCTP checksumming for IPVS with gso packets,
	 from Ismael Luceno.

Patch #2 honor dormant flag from netdev event path to fix a possible
	 double hook unregistration.

* tag 'nf-24-04-25' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: honor table dormant flag from netdev release event path
  ipvs: Fix checksumming on GSO of SCTP packets
====================

Link: https://lore.kernel.org/r/20240425090149.1359547-1-pablo@netfilter.orgSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      e8baa63f
    • Kuniyuki Iwashima's avatar
      af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc(). · 1971d13f
      Kuniyuki Iwashima authored 
      syzbot reported a lockdep splat regarding unix_gc_lock and
unix_state_lock().

One is called from recvmsg() for a connected socket, and another
is called from GC for TCP_LISTEN socket.

So, the splat is false-positive.

Let's add a dedicated lock class for the latter to suppress the splat.

Note that this change is not necessary for net-next.git as the issue
is only applied to the old GC impl.

[0]:
WARNING: possible circular locking dependency detected
6.9.0-rc5-syzkaller-00007-g4d200843 #0 Not tainted
 -----------------------------------------------------
kworker/u8:1/11 is trying to acquire lock:
ffff88807cea4e70 (&u->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88807cea4e70 (&u->lock){+.+.}-{2:2}, at: __unix_gc+0x40e/0xf70 net/unix/garbage.c:302

but task is already holding lock:
ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

 -> #1 (unix_gc_lock){+.+.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       unix_notinflight+0x13d/0x390 net/unix/garbage.c:140
       unix_detach_fds net/unix/af_unix.c:1819 [inline]
       unix_destruct_scm+0x221/0x350 net/unix/af_unix.c:1876
       skb_release_head_state+0x100/0x250 net/core/skbuff.c:1188
       skb_release_all net/core/skbuff.c:1200 [inline]
       __kfree_skb net/core/skbuff.c:1216 [inline]
       kfree_skb_reason+0x16d/0x3b0 net/core/skbuff.c:1252
       kfree_skb include/linux/skbuff.h:1262 [inline]
       manage_oob net/unix/af_unix.c:2672 [inline]
       unix_stream_read_generic+0x1125/0x2700 net/unix/af_unix.c:2749
       unix_stream_splice_read+0x239/0x320 net/unix/af_unix.c:2981
       do_splice_read fs/splice.c:985 [inline]
       splice_file_to_pipe+0x299/0x500 fs/splice.c:1295
       do_splice+0xf2d/0x1880 fs/splice.c:1379
       __do_splice fs/splice.c:1436 [inline]
       __do_sys_splice fs/splice.c:1652 [inline]
       __se_sys_splice+0x331/0x4a0 fs/splice.c:1634
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> #0 (&u->lock){+.+.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       __unix_gc+0x40e/0xf70 net/unix/garbage.c:302
       process_one_work kernel/workqueue.c:3254 [inline]
       process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335
       worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
       kthread+0x2f0/0x390 kernel/kthread.c:388
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(unix_gc_lock);
                               lock(&u->lock);
                               lock(unix_gc_lock);
  lock(&u->lock);

 *** DEADLOCK ***

3 locks held by kworker/u8:1/11:
 #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335
 #1: ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335
 #2: ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #2: ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261

stack backtrace:
CPU: 0 PID: 11 Comm: kworker/u8:1 Not tainted 6.9.0-rc5-syzkaller-00007-g4d200843 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound __unix_gc
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 __unix_gc+0x40e/0xf70 net/unix/garbage.c:302
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Fixes: 47d8ac01 ("af_unix: Fix garbage collector racing against connect()")
Reported-and-tested-by: syzbot+fa379358c28cc87cc307@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fa379358c28cc87cc307Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240424170443.9832-1-kuniyu@amazon.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      1971d13f
    • Peter Münster's avatar
      net: b44: set pause params only when interface is up · e3eb7dd4
      Peter Münster authored 
      b44_free_rings() accesses b44::rx_buffers (and ::tx_buffers)
unconditionally, but b44::rx_buffers is only valid when the
device is up (they get allocated in b44_open(), and deallocated
again in b44_close()), any other time these are just a NULL pointers.

So if you try to change the pause params while the network interface
is disabled/administratively down, everything explodes (which likely
netifd tries to do).

Link: https://github.com/openwrt/openwrt/issues/13789
Fixes: 1da177e4 (Linux-2.6.12-rc2)
Cc: stable@vger.kernel.org
Reported-by: default avatarPeter Münster <pm@a16n.net>
Suggested-by: default avatarJonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: default avatarVaclav Svoboda <svoboda@neng.cz>
Tested-by: default avatarPeter Münster <pm@a16n.net>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarPeter Münster <pm@a16n.net>
Reviewed-by: default avatarMichael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/87y192oolj.fsf@a16n.netSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      e3eb7dd4
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