On Wed, Nov 19, 2014 at 12:41 PM, Julia Lawall <julia.lawall at lip6.fr> wrote: >> +// Comments: There are false positives in crypto/ where they are >> actually freed. > > I didn't really understand this comment. I ran the semantic patch and got > around 10 results, but it wasn't clear to me how to see which were false > positives. I mean false positives in code inside directory crypto/ where this subsystem lives. ./arch/x86/crypto/fpu.c:143:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/algapi.c:846:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/lrw.c:378:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/ecb.c:163:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/ctr.c:242:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/ctr.c:419:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/ctr.c:428:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/pcbc.c:273:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/cts.c:329:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/cbc.c:267:1-6: WARNING: invalid free of crypto_alloc_* allocated data ./crypto/xts.c:340:1-6: WARNING: invalid free of crypto_alloc_* allocated data This is kfree calls on error paths in constructors or in destructors which actually frees memory when crypto_free_* is called. > > I would suggest to extend the rule a little bit to include information > about where the allocation call is: Not sure if this is necessary. This part of crypto-api is simple. > > /// > /// Structures allocated by crypto_alloc_* must be freed using crypto_free_*. > /// This finds freeing them by kfree. > /// > // Confidence: Moderate > // Copyright: (C) 2014 Konstantin Khlebnikov, GPLv2. > // Comments: There are false positives in crypto/ where they are actually freed. > // Keywords: crypto, kfree > // Options: --no-includes --include-headers > > virtual org > virtual report > virtual context > > @r depends on context || org || report@ > expression x; > position p1; > @@ > > ( > x = crypto_alloc_base at p1(...) > | > x = crypto_alloc_cipher at p1(...) > | > x = crypto_alloc_ablkcipher at p1(...) > | > x = crypto_alloc_aead at p1(...) > | > x = crypto_alloc_instance at p1(...) > | > x = crypto_alloc_instance2 at p1(...) > | > x = crypto_alloc_comp at p1(...) > | > x = crypto_alloc_pcomp at p1(...) > | > x = crypto_alloc_hash at p1(...) > | > x = crypto_alloc_ahash at p1(...) > | > x = crypto_alloc_shash at p1(...) > | > x = crypto_alloc_rng at p1(...) > ) > > @pb@ > expression r.x; > position p; > @@ > > * kfree at p(x) > > @script:python depends on org@ > p << pb.p; > p1 << r.p1; > @@ > > msg="WARNING: invalid free of crypto_alloc_* allocated data" > coccilib.org.print_todo(p[0], msg) > coccilib.org.print_link(p1[0], "allocation") > > @script:python depends on report@ > p << pb.p; > p1 << r.p1; > @@ > > msg="WARNING: invalid free of crypto_alloc_* allocated data, allocated on line %s" % (p1[0].line) > coccilib.report.print_report(p[0], msg) > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
