NetBSD Kernel Sanitizers

[Palle Lyckegaard <palle%netbsd.org@localhost>]

Hello.

While trying to track down a memory corruption issue on sparc64/sun4v I noticed kernel_sanitizers(7) and the
lack of support on platforms other than amd64 and arm/aarch64.

Some of the sanitizers requires MD code, e.g. KASAN, KCSAN and KMSAM, whereas KUBSAN should be available on all platforms.

Trying to build with KUBSAN enabled on a few selected ports seems to cause build issues:

sparc/sparc64:

In function 'be16enc',
    inlined from 'uuid_enc_be' at /home/palle/netbsd/git/src/sys/kern/kern_uuid.c:178:2:
    /home/palle/netbsd/git/src/sys/sys/endian.h:204:9: error: '__builtin_memcpy' offset [0, 1] is out of the bounds [0, 0] [-Werror=array-bounds]
      204 |         __builtin_memcpy(dst, &u, sizeof(u)); \
	    |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	    /home/palle/netbsd/git/src/sys/sys/endian.h:207:1: note: in expansion of macro '__GEN_ENDIAN_ENC'
	      207 | __GEN_ENDIAN_ENC(16, be)
		    | ^~~~~~~~~~~~~~~~
		    In function 'be16dec',
		     
evbppc:

In file included from /home/palle/netbsd/git/src/sys/dev/rasops/rasops2.c:49:
/home/palle/netbsd/git/src/sys/dev/rasops/rasops_bitops.h: In function 'rasops2_copycols':
/home/palle/netbsd/git/src/sys/dev/rasops/rasops_masks.h:85:50: error: array subscript 2147483616 is above array bounds of 'const uint32_t[33]' {aka 'const unsigned int[33]'} [-Werror=array-bounds]
   85 |                 (dp)[1] = ((dp)[1] & rasops_rmask[n]) |                 \
	 |                                      ~~~~~~~~~~~~^~~
	 /home/palle/netbsd/git/src/sys/dev/rasops/rasops_bitops.h:279:25: note: in expansion of macro 'PUTBITS'
	   279 |                         PUTBITS(tmp, db, num, drp);
		 |                         ^~~~~~~
		 /home/palle/netbsd/git/src/sys/dev/rasops/rasops_masks.h:92:25: note: while referencing 'rasops_rmask'
		    92 | extern const uint32_t   rasops_rmask[32 + 1];
			  |                         ^~~~~~~~~~~~
			  /home/palle/netbsd/git/src/sys/dev/rasops/rasops_masks.h:86:56: error: array subscript 2147483616 is above array bounds of 'const uint32_t[33]' {aka 'const unsigned int[33]'} [-Werror=array-bounds]
			     86 |                         (MBL(sw, 32-(x)) & rasops_lmask[n]);            \
				   |                                            ~~~~~~~~~~~~^~~
				   /home/palle/netbsd/git/src/sys/dev/rasops/rasops_bitops.h:279:25: note: in expansion of macro 'PUTBITS'
				     279 |                         PUTBITS(tmp, db, num, drp);
					   |                         ^~~~~~~
					   /home/palle/netbsd/git/src/sys/dev/rasops/rasops_masks.h:91:25: note: while referencing 'rasops_lmask'
					      91 | extern const uint32_t   rasops_lmask[32 + 1];
						    |                         ^~~~~~~~~~~~


evbmips64-el:

-- kern-MALTA32 ---
--- aes_bear.o ---
In function 'le32dec',
    inlined from 'aesbear_cbc_dec.part.0' at /home/palle/netbsd/git/src/sys/crypto/aes/aes_bear.c:236:8:
    /home/palle/netbsd/git/src/sys/sys/endian.h:220:9: error: '__builtin_memcpy' offset [0, 3] is out of the bounds [0, 0] [-Werror=array-bounds]
      220 |         __builtin_memcpy(&u, buf, sizeof(u)); \
	    |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	    /home/palle/netbsd/git/src/sys/sys/endian.h:228:1: note: in expansion of macro '__GEN_ENDIAN_DEC'
	      228 | __GEN_ENDIAN_DEC(32, le)
		    | ^~~~~~~~~~~~~~~~
		    --


evbmips64-eb:

--- kern-MALTA32 ---
In function 'be16dec',
    inlined from 'uuid_dec_be' at /home/palle/netbsd/git/src/sys/kern/kern_uuid.c:193:19:
    /home/palle/netbsd/git/src/sys/sys/endian.h:220:9: error: '__builtin_memcpy' offset [0, 1] is out of the bounds [0, 0] [-Werror=array-bounds]
      220 |         __builtin_memcpy(&u, buf, sizeof(u)); \
	    |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	    /home/palle/netbsd/git/src/sys/sys/endian.h:224:1: note: in expansion of macro '__GEN_ENDIAN_DEC'
	      224 | __GEN_ENDIAN_DEC(16, be)
		    | ^~~~~~~~~~~~~~~~


riscv32:

bmake[2]: stopped making "all" in /home/palle/netbsd/build/riscv32/objdir/sys/arch/riscv/compile/GENERIC
--- chacha_ref.o ---
In function 'le32dec',
    inlined from 'chacha_stream_ref' at /home/palle/netbsd/git/src/sys/crypto/chacha/chacha_ref.c:138:7:
    /home/palle/netbsd/git/src/sys/sys/endian.h:220:9: error: '__builtin_memcpy' offset [0, 3] is out of the bounds [0, 0] [-Werror=array-bounds]
      220 |         __builtin_memcpy(&u, buf, sizeof(u)); \
	    |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	    /home/palle/netbsd/git/src/sys/sys/endian.h:228:1: note: in expansion of macro '__GEN_ENDIAN_DEC'
	      228 | __GEN_ENDIAN_DEC(32, le)
		    | ^~~~~~~~~~~~~~~~


riscv64:

nbmake[2]: stopped making "all" in /home/palle/netbsd/build/riscv64/objdir/sys/arch/riscv/compile/GENERIC64
--- chacha_ref.o ---
In function 'le32dec',
    inlined from 'chacha_stream_ref' at /home/palle/netbsd/git/src/sys/crypto/chacha/chacha_ref.c:138:7:
    /home/palle/netbsd/git/src/sys/sys/endian.h:220:9: error: '__builtin_memcpy' offset [0, 3] is out of the bounds [0, 0] [-Werror=array-bounds]
      220 |         __builtin_memcpy(&u, buf, sizeof(u)); \
	    |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	    /home/palle/netbsd/git/src/sys/sys/endian.h:228:1: note: in expansion of macro '__GEN_ENDIAN_DEC'
	      228 | __GEN_ENDIAN_DEC(32, le)
		    | ^~~~~~~~~~~~~~~~
		    ---




It would be nice to have KUBSAN enabled when the daily CI build jobs are running.

Would it make sense to create a GENERIC.KUBSAN config for all ports so build issues as shown above are caught?

And what about running the daily test runs with the supported kernel sanitizers enabled as well?

It's a shame that such useful functionality is not enabled by default at least when the daily test runs are executed.


Regards
Palle