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Remove unnecessary max-allocation limit checks from bytecode runtime

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Allocations for bytecode signatures to work need not check against the
memory allocation limit, as bytecode signatures are considered trusted
user input.

You may note that I did not remove allocation limits from the bytecode
API functions that may be called by the signatures such as adding json
objects, hashsets, lzma and bz2 decompressors, etc. This is because it
is likely that a bytecode signature may call them more times based on
the structure of the file being scanned - particularly for the json objects.
This commit is contained in:
Micah Snyder 2024-01-09 16:28:51 -05:00 • committed by Micah Snyder
parent 9dc80eb8e7
commit 609ace2e3c
3 changed files with 50 additions and 50 deletions
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38
libclamav/bytecode_vm.c
View file

@ -286,17 +286,17 @@ static always_inline struct stack_entry *pop_stack(struct stack *stack,
*(uint8_t *)&values[p] = x
#define WRITE16(p, x) \
CHECK_GT(func->numBytes, p + 1); \
CHECK_EQ((p)&1, 0); \
CHECK_EQ((p) & 1, 0); \
TRACE_W(x, p, 16); \
*(uint16_t *)&values[p] = x
#define WRITE32(p, x) \
CHECK_GT(func->numBytes, p + 3); \
CHECK_EQ((p)&3, 0); \
CHECK_EQ((p) & 3, 0); \
TRACE_W(x, p, 32); \
*(uint32_t *)&values[p] = x
#define WRITE64(p, x) \
CHECK_GT(func->numBytes, p + 7); \
CHECK_EQ((p)&7, 0); \
CHECK_EQ((p) & 7, 0); \
TRACE_W(x, p, 64); \
*(uint64_t *)&values[p] = x
#define WRITEP(x, p) \
@ -346,16 +346,16 @@ static always_inline struct stack_entry *pop_stack(struct stack *stack,
} \
TRACE_R(x) \
}
#define READPOP(x, p, asize) \
{ \
if ((p)&0x40000000) { \
unsigned ptr__ = (p)&0xbfffffff; \
CHECK_GT(func->numBytes, ptr__); \
TRACE_PTR(ptr__, asize); \
x = (void *)&values[ptr__]; \
} else { \
READP(x, p, asize) \
} \
#define READPOP(x, p, asize) \
{ \
if ((p) & 0x40000000) { \
unsigned ptr__ = (p) & 0xbfffffff; \
CHECK_GT(func->numBytes, ptr__); \
TRACE_PTR(ptr__, asize); \
x = (void *)&values[ptr__]; \
} else { \
READP(x, p, asize) \
} \
}
#define READOLD8(x, p) \
@ -364,17 +364,17 @@ static always_inline struct stack_entry *pop_stack(struct stack *stack,
TRACE_R(x)
#define READOLD16(x, p) \
CHECK_GT(func->numBytes, p + 1); \
CHECK_EQ((p)&1, 0); \
CHECK_EQ((p) & 1, 0); \
x = *(uint16_t *)&old_values[p]; \
TRACE_R(x)
#define READOLD32(x, p) \
CHECK_GT(func->numBytes, p + 3); \
CHECK_EQ((p)&3, 0); \
CHECK_EQ((p) & 3, 0); \
x = *(uint32_t *)&old_values[p]; \
TRACE_R(x)
#define READOLD64(x, p) \
CHECK_GT(func->numBytes, p + 7); \
CHECK_EQ((p)&7, 0); \
CHECK_EQ((p) & 7, 0); \
x = *(uint64_t *)&old_values[p]; \
TRACE_R(x)
@ -596,8 +596,8 @@ static inline int64_t ptr_register_stack(struct ptr_infos *infos,
uint32_t off, uint32_t size)
{
unsigned n = infos->nstacks + 1;
struct ptr_info *sinfos = cli_max_realloc(infos->stack_infos,
sizeof(*sinfos) * n);
struct ptr_info *sinfos = cli_safer_realloc(infos->stack_infos,
sizeof(*sinfos) * n);
if (!sinfos)
return 0;
infos->stack_infos = sinfos;
@ -613,7 +613,7 @@ static inline int64_t ptr_register_glob_fixedid(struct ptr_infos *infos,
{
struct ptr_info *sinfos;
if (n > infos->nglobs) {
sinfos = cli_max_realloc(infos->glob_infos, sizeof(*sinfos) * n);
sinfos = cli_safer_realloc(infos->glob_infos, sizeof(*sinfos) * n);
if (!sinfos)
return 0;
memset(sinfos + infos->nglobs, 0, (n - infos->nglobs) * sizeof(*sinfos));