Revision 447ac906e189535e77dcb1f4bbe3f1bc917d4c12 authored by Patrick Steinhardt on 01 December 2022, 14:45:31 UTC, committed by Junio C Hamano on 05 December 2022, 06:14:16 UTC
The `struct attr_stack` tracks the stack of all patterns together with their attributes. When parsing a gitattributes file that has more than 2^31 such patterns though we may trigger multiple out-of-bounds reads on 64 bit platforms. This is because while the `num_matches` variable is an unsigned integer, we always use a signed integer to iterate over them. I have not been able to reproduce this issue due to memory constraints on my systems. But despite the out-of-bounds reads, the worst thing that can seemingly happen is to call free(3P) with a garbage pointer when calling `attr_stack_free()`. Fix this bug by using unsigned integers to iterate over the array. While this makes the iteration somewhat awkward when iterating in reverse, it is at least better than knowingly running into an out-of-bounds read. While at it, convert the call to `ALLOC_GROW` to use `ALLOC_GROW_BY` instead. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 34ace8b
commit-slab-decl.h
#ifndef COMMIT_SLAB_DECL_H
#define COMMIT_SLAB_DECL_H
/* allocate ~512kB at once, allowing for malloc overhead */
#ifndef COMMIT_SLAB_SIZE
#define COMMIT_SLAB_SIZE (512*1024-32)
#endif
#define declare_commit_slab(slabname, elemtype) \
\
struct slabname { \
unsigned slab_size; \
unsigned stride; \
unsigned slab_count; \
elemtype **slab; \
}
/*
* Statically initialize a commit slab named "var". Note that this
* evaluates "stride" multiple times! Example:
*
* struct indegree indegrees = COMMIT_SLAB_INIT(1, indegrees);
*
*/
#define COMMIT_SLAB_INIT(stride, var) { \
COMMIT_SLAB_SIZE / sizeof(**((var).slab)) / (stride), \
(stride), 0, NULL \
}
#define declare_commit_slab_prototypes(slabname, elemtype) \
\
void init_ ##slabname## _with_stride(struct slabname *s, unsigned stride); \
void init_ ##slabname(struct slabname *s); \
void clear_ ##slabname(struct slabname *s); \
void deep_clear_ ##slabname(struct slabname *s, void (*free_fn)(elemtype *ptr)); \
elemtype *slabname## _at_peek(struct slabname *s, const struct commit *c, int add_if_missing); \
elemtype *slabname## _at(struct slabname *s, const struct commit *c); \
elemtype *slabname## _peek(struct slabname *s, const struct commit *c)
#define define_shared_commit_slab(slabname, elemtype) \
declare_commit_slab(slabname, elemtype); \
declare_commit_slab_prototypes(slabname, elemtype)
#endif /* COMMIT_SLAB_DECL_H */
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