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  1. 06 Jul, 2022 3 commits
  3. 05 Jul, 2022 7 commits
  5. 04 Jul, 2022 20 commits
  7. 03 Jul, 2022 1 commit
    • David S. Miller's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf · 280e3a85
      David S. Miller authored 
      Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Insufficient validation of element datatype and length in
   nft_setelem_parse_data(). At least commit 7d740264 updates
   maximum element data area up to 64 bytes when only 16 bytes
   where supported at the time. Support for larger element size
   came later in fdb9c405 though. Picking this older commit
   as Fixes: tag to be safe than sorry.

2) Memleak in pipapo destroy path, reproducible when transaction
   in aborted. This is already triggering in the existing netfilter
   test infrastructure since more recent new tests are covering this
   path.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      280e3a85
  9. 02 Jul, 2022 5 commits
  11. 01 Jul, 2022 4 commits
    • Daniel Borkmann's avatar
      bpf, selftests: Add verifier test case for jmp32's jeq/jne · a49b8ce7
      Daniel Borkmann authored 
      Add a test case to trigger the verifier's incorrect conclusion in the
case of jmp32's jeq/jne. Also here, make use of dead code elimination,
so that we can see the verifier bailing out on unfixed kernels.

Before:

  # ./test_verifier 724
  #724/p jeq32/jne32: bounds checking FAIL
  Failed to load prog 'Permission denied'!
  R4 !read_ok
  verification time 8 usec
  stack depth 0
  processed 8 insns (limit 1000000) max_states_per_insn 0 total_states 1 peak_states 1 mark_read 0
  Summary: 0 PASSED, 0 SKIPPED, 1 FAILED

After:

  # ./test_verifier 724
  #724/p jeq32/jne32: bounds checking OK
  Summary: 1 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220701124727.11153-4-daniel@iogearbox.net
      a49b8ce7
    • Daniel Borkmann's avatar
      bpf, selftests: Add verifier test case for imm=0,umin=0,umax=1 scalar · 73c4936f
      Daniel Borkmann authored 
      Add a test case to trigger the constant scalar issue which leaves the
register in scalar(imm=0,umin=0,umax=1,var_off=(0x0; 0x0)) state. Make
use of dead code elimination, so that we can see the verifier bailing
out on unfixed kernels. For the condition, we use jle given it checks
on umax bound.

Before:

  # ./test_verifier 743
  #743/p jump & dead code elimination FAIL
  Failed to load prog 'Permission denied'!
  R4 !read_ok
  verification time 11 usec
  stack depth 0
  processed 13 insns (limit 1000000) max_states_per_insn 0 total_states 1 peak_states 1 mark_read 1
  Summary: 0 PASSED, 0 SKIPPED, 1 FAILED

After:

  # ./test_verifier 743
  #743/p jump & dead code elimination OK
  Summary: 1 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220701124727.11153-3-daniel@iogearbox.net
      73c4936f
    • Daniel Borkmann's avatar
      bpf: Fix insufficient bounds propagation from adjust_scalar_min_max_vals · 3844d153
      Daniel Borkmann authored 
      Kuee reported a corner case where the tnum becomes constant after the call
to __reg_bound_offset(), but the register's bounds are not, that is, its
min bounds are still not equal to the register's max bounds.

This in turn allows to leak pointers through turning a pointer register as
is into an unknown scalar via adjust_ptr_min_max_vals().

Before:

  func#0 @0
  0: R1=ctx(off=0,imm=0,umax=0,var_off=(0x0; 0x0)) R10=fp(off=0,imm=0,umax=0,var_off=(0x0; 0x0))
  0: (b7) r0 = 1                        ; R0_w=scalar(imm=1,umin=1,umax=1,var_off=(0x1; 0x0))
  1: (b7) r3 = 0                        ; R3_w=scalar(imm=0,umax=0,var_off=(0x0; 0x0))
  2: (87) r3 = -r3                      ; R3_w=scalar()
  3: (87) r3 = -r3                      ; R3_w=scalar()
  4: (47) r3 |= 32767                   ; R3_w=scalar(smin=-9223372036854743041,umin=32767,var_off=(0x7fff; 0xffffffffffff8000),s32_min=-2147450881)
  5: (75) if r3 s>= 0x0 goto pc+1       ; R3_w=scalar(umin=9223372036854808575,var_off=(0x8000000000007fff; 0x7fffffffffff8000),s32_min=-2147450881,u32_min=32767)
  6: (95) exit

  from 5 to 7: R0=scalar(imm=1,umin=1,umax=1,var_off=(0x1; 0x0)) R1=ctx(off=0,imm=0,umax=0,var_off=(0x0; 0x0)) R3=scalar(umin=32767,umax=9223372036854775807,var_off=(0x7fff; 0x7fffffffffff8000),s32_min=-2147450881) R10=fp(off=0,imm=0,umax=0,var_off=(0x0; 0x0))
  7: (d5) if r3 s<= 0x8000 goto pc+1    ; R3=scalar(umin=32769,umax=9223372036854775807,var_off=(0x7fff; 0x7fffffffffff8000),s32_min=-2147450881,u32_min=32767)
  8: (95) exit

  from 7 to 9: R0=scalar(imm=1,umin=1,umax=1,var_off=(0x1; 0x0)) R1=ctx(off=0,imm=0,umax=0,var_off=(0x0; 0x0)) R3=scalar(umin=32767,umax=32768,var_off=(0x7fff; 0x8000)) R10=fp(off=0,imm=0,umax=0,var_off=(0x0; 0x0))
  9: (07) r3 += -32767                  ; R3_w=scalar(imm=0,umax=1,var_off=(0x0; 0x0))  <--- [*]
  10: (95) exit

What can be seen here is that R3=scalar(umin=32767,umax=32768,var_off=(0x7fff;
0x8000)) after the operation R3 += -32767 results in a 'malformed' constant, that
is, R3_w=scalar(imm=0,umax=1,var_off=(0x0; 0x0)). Intersecting with var_off has
not been done at that point via __update_reg_bounds(), which would have improved
the umax to be equal to umin.

Refactor the tnum <> min/max bounds information flow into a reg_bounds_sync()
helper and use it consistently everywhere. After the fix, bounds have been
corrected to R3_w=scalar(imm=0,umax=0,var_off=(0x0; 0x0)) and thus the register
is regarded as a 'proper' constant scalar of 0.

After:

  func#0 @0
  0: R1=ctx(off=0,imm=0,umax=0,var_off=(0x0; 0x0)) R10=fp(off=0,imm=0,umax=0,var_off=(0x0; 0x0))
  0: (b7) r0 = 1                        ; R0_w=scalar(imm=1,umin=1,umax=1,var_off=(0x1; 0x0))
  1: (b7) r3 = 0                        ; R3_w=scalar(imm=0,umax=0,var_off=(0x0; 0x0))
  2: (87) r3 = -r3                      ; R3_w=scalar()
  3: (87) r3 = -r3                      ; R3_w=scalar()
  4: (47) r3 |= 32767                   ; R3_w=scalar(smin=-9223372036854743041,umin=32767,var_off=(0x7fff; 0xffffffffffff8000),s32_min=-2147450881)
  5: (75) if r3 s>= 0x0 goto pc+1       ; R3_w=scalar(umin=9223372036854808575,var_off=(0x8000000000007fff; 0x7fffffffffff8000),s32_min=-2147450881,u32_min=32767)
  6: (95) exit

  from 5 to 7: R0=scalar(imm=1,umin=1,umax=1,var_off=(0x1; 0x0)) R1=ctx(off=0,imm=0,umax=0,var_off=(0x0; 0x0)) R3=scalar(umin=32767,umax=9223372036854775807,var_off=(0x7fff; 0x7fffffffffff8000),s32_min=-2147450881) R10=fp(off=0,imm=0,umax=0,var_off=(0x0; 0x0))
  7: (d5) if r3 s<= 0x8000 goto pc+1    ; R3=scalar(umin=32769,umax=9223372036854775807,var_off=(0x7fff; 0x7fffffffffff8000),s32_min=-2147450881,u32_min=32767)
  8: (95) exit

  from 7 to 9: R0=scalar(imm=1,umin=1,umax=1,var_off=(0x1; 0x0)) R1=ctx(off=0,imm=0,umax=0,var_off=(0x0; 0x0)) R3=scalar(umin=32767,umax=32768,var_off=(0x7fff; 0x8000)) R10=fp(off=0,imm=0,umax=0,var_off=(0x0; 0x0))
  9: (07) r3 += -32767                  ; R3_w=scalar(imm=0,umax=0,var_off=(0x0; 0x0))  <--- [*]
  10: (95) exit

Fixes: b03c9f9f ("bpf/verifier: track signed and unsigned min/max values")
Reported-by: default avatarKuee K1r0a <liulin063@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220701124727.11153-2-daniel@iogearbox.net
      3844d153
    • Daniel Borkmann's avatar
      bpf: Fix incorrect verifier simulation around jmp32's jeq/jne · a12ca627
      Daniel Borkmann authored 
      Kuee reported a quirk in the jmp32's jeq/jne simulation, namely that the
register value does not match expectations for the fall-through path. For
example:

Before fix:

  0: R1=ctx(off=0,imm=0) R10=fp0
  0: (b7) r2 = 0                        ; R2_w=P0
  1: (b7) r6 = 563                      ; R6_w=P563
  2: (87) r2 = -r2                      ; R2_w=Pscalar()
  3: (87) r2 = -r2                      ; R2_w=Pscalar()
  4: (4c) w2 |= w6                      ; R2_w=Pscalar(umin=563,umax=4294967295,var_off=(0x233; 0xfffffdcc),s32_min=-2147483085) R6_w=P563
  5: (56) if w2 != 0x8 goto pc+1        ; R2_w=P571  <--- [*]
  6: (95) exit
  R0 !read_ok

After fix:

  0: R1=ctx(off=0,imm=0) R10=fp0
  0: (b7) r2 = 0                        ; R2_w=P0
  1: (b7) r6 = 563                      ; R6_w=P563
  2: (87) r2 = -r2                      ; R2_w=Pscalar()
  3: (87) r2 = -r2                      ; R2_w=Pscalar()
  4: (4c) w2 |= w6                      ; R2_w=Pscalar(umin=563,umax=4294967295,var_off=(0x233; 0xfffffdcc),s32_min=-2147483085) R6_w=P563
  5: (56) if w2 != 0x8 goto pc+1        ; R2_w=P8  <--- [*]
  6: (95) exit
  R0 !read_ok

As can be seen on line 5 for the branch fall-through path in R2 [*] is that
given condition w2 != 0x8 is false, verifier should conclude that r2 = 8 as
upper 32 bit are known to be zero. However, verifier incorrectly concludes
that r2 = 571 which is far off.

The problem is it only marks false{true}_reg as known in the switch for JE/NE
case, but at the end of the function, it uses {false,true}_{64,32}off to
update {false,true}_reg->var_off and they still hold the prior value of
{false,true}_reg->var_off before it got marked as known. The subsequent
__reg_combine_32_into_64() then propagates this old var_off and derives new
bounds. The information between min/max bounds on {false,true}_reg from
setting the register to known const combined with the {false,true}_reg->var_off
based on the old information then derives wrong register data.

Fix it by detangling the BPF_JEQ/BPF_JNE cases and updating relevant
{false,true}_{64,32}off tnums along with the register marking to known
constant.

Fixes: 3f50f132 ("bpf: Verifier, do explicit ALU32 bounds tracking")
Reported-by: default avatarKuee K1r0a <liulin063@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220701124727.11153-1-daniel@iogearbox.net
      a12ca627
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