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redo result buffer allocation, to avoid dynamic allocations:

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-use exponentially growing buffer sizes instead of just linear extension
-drop the dynamic allocation of buffer metadata introduced in rev.1.8 --
 if the initial array is not sufficient something is wrong
-apply some (arbitrary, heuristic) limit so that compressed data
 which extract into insane amounts of constant data don't kill the system
This addresses PR kern/36864 by Wolfgang Stukenbrock. Some tuning
might be useful, but hopefully this is an improvement already.
This commit is contained in:
drochner 2011-02-18 22:02:09 +00:00
parent e786622161
commit 896d946a93
1 changed files with 9 additions and 24 deletions
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33
sys/opencrypto/deflate.c
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@ -1,4 +1,4 @@
/* $NetBSD: deflate.c,v 1.17 2011/02/18 10:50:56 drochner Exp $ */ /* $NetBSD: deflate.c,v 1.18 2011/02/18 22:02:09 drochner Exp $ */
/* $FreeBSD: src/sys/opencrypto/deflate.c,v 1.1.2.1 2002/11/21 23:34:23 sam Exp $ */ /* $FreeBSD: src/sys/opencrypto/deflate.c,v 1.1.2.1 2002/11/21 23:34:23 sam Exp $ */
/* $OpenBSD: deflate.c,v 1.3 2001/08/20 02:45:22 hugh Exp $ */ /* $OpenBSD: deflate.c,v 1.3 2001/08/20 02:45:22 hugh Exp $ */
@ -35,7 +35,7 @@
*/ */
#include <sys/cdefs.h> #include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: deflate.c,v 1.17 2011/02/18 10:50:56 drochner Exp $"); __KERNEL_RCSID(0, "$NetBSD: deflate.c,v 1.18 2011/02/18 22:02:09 drochner Exp $");
#include <sys/types.h> #include <sys/types.h>
#include <sys/malloc.h> #include <sys/malloc.h>
@ -79,16 +79,10 @@ deflate_global(u_int8_t *data, u_int32_t size, int decomp, u_int8_t **out)
u_int8_t *output; u_int8_t *output;
u_int32_t count, result, tocopy; u_int32_t count, result, tocopy;
int error, i, j; int error, i, j;
struct deflate_buf *buf, *tmp; struct deflate_buf buf[ZBUF];
size_t len;
DPRINTF(("deflate_global: size %d\n", size)); DPRINTF(("deflate_global: size %d\n", size));
len = ZBUF;
buf = malloc(len*sizeof(struct deflate_buf), M_CRYPTO_DATA, M_NOWAIT);
if (buf == NULL)
return 0;
memset(&zbuf, 0, sizeof(z_stream)); memset(&zbuf, 0, sizeof(z_stream));
zbuf.next_in = data; /* data that is going to be processed */ zbuf.next_in = data; /* data that is going to be processed */
zbuf.zalloc = ocf_zalloc; zbuf.zalloc = ocf_zalloc;
@ -110,7 +104,7 @@ deflate_global(u_int8_t *data, u_int32_t size, int decomp, u_int8_t **out)
} }
buf[0].out = malloc(buf[0].size, M_CRYPTO_DATA, M_NOWAIT); buf[0].out = malloc(buf[0].size, M_CRYPTO_DATA, M_NOWAIT);
if (buf[0].out == NULL) if (buf[0].out == NULL)
goto bad3; return 0;
i = 1; i = 1;
zbuf.next_out = buf[0].out; zbuf.next_out = buf[0].out;
@ -142,21 +136,15 @@ deflate_global(u_int8_t *data, u_int32_t size, int decomp, u_int8_t **out)
else if (error != Z_OK) else if (error != Z_OK)
goto bad; goto bad;
else if (zbuf.avail_out == 0) { else if (zbuf.avail_out == 0) {
if (i == len) {
len += ZBUF;
tmp = realloc(buf,len*sizeof(struct deflate_buf),
M_CRYPTO_DATA, M_NOWAIT);
if (tmp == NULL)
goto bad;
buf = tmp;
}
/* we need more output space, allocate size */ /* we need more output space, allocate size */
buf[i].out = malloc(size, M_CRYPTO_DATA, M_NOWAIT); int nextsize = buf[i-1].size * 2;
if (i == ZBUF || nextsize > 1000000)
goto bad;
buf[i].out = malloc(nextsize, M_CRYPTO_DATA, M_NOWAIT);
if (buf[i].out == NULL) if (buf[i].out == NULL)
goto bad; goto bad;
zbuf.next_out = buf[i].out; zbuf.next_out = buf[i].out;
buf[i].size = size; zbuf.avail_out = buf[i].size = nextsize;
zbuf.avail_out = buf[i].size;
i++; i++;
} }
} }
@ -181,7 +169,6 @@ deflate_global(u_int8_t *data, u_int32_t size, int decomp, u_int8_t **out)
} else { } else {
*out = buf[0].out; *out = buf[0].out;
} }
free(buf, M_CRYPTO_DATA);
if (decomp) if (decomp)
inflateEnd(&zbuf); inflateEnd(&zbuf);
else else
@ -196,8 +183,6 @@ bad:
bad2: bad2:
for (j = 0; j < i; j++) for (j = 0; j < i; j++)
free(buf[j].out, M_CRYPTO_DATA); free(buf[j].out, M_CRYPTO_DATA);
bad3:
free(buf, M_CRYPTO_DATA);
return 0; return 0;
} }