From 836b2fe544a5e9b5ce116622cb36fba33838c6fd Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 01:33:23 -0700 Subject: selftests/bpf: Check that JMP32 pointer vs zero jumps are not predicted Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which the verifier used to skip, contains an out of bounds map value access, hence w/o the previous patch the program is accepted. See previous patch for detailed description. Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- tools/lib/slab.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 tools/lib/slab.c (limited to 'tools/lib/slab.c') diff --git a/tools/lib/slab.c b/tools/lib/slab.c new file mode 100644 index 000000000..981a21404 --- /dev/null +++ b/tools/lib/slab.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +#include +#include +#include +#include + +int kmalloc_nr_allocated; +int kmalloc_verbose; + +void *kmalloc(size_t size, gfp_t gfp) +{ + void *ret; + + if (!(gfp & __GFP_DIRECT_RECLAIM)) + return NULL; + + ret = malloc(size); + uatomic_inc(&kmalloc_nr_allocated); + if (kmalloc_verbose) + printf("Allocating %p from malloc\n", ret); + if (gfp & __GFP_ZERO) + memset(ret, 0, size); + return ret; +} + +void kfree(void *p) +{ + if (!p) + return; + uatomic_dec(&kmalloc_nr_allocated); + if (kmalloc_verbose) + printf("Freeing %p to malloc\n", p); + free(p); +} + +void *kmalloc_array(size_t n, size_t size, gfp_t gfp) +{ + void *ret; + + if (!(gfp & __GFP_DIRECT_RECLAIM)) + return NULL; + + ret = calloc(n, size); + uatomic_inc(&kmalloc_nr_allocated); + if (kmalloc_verbose) + printf("Allocating %p from calloc\n", ret); + if (gfp & __GFP_ZERO) + memset(ret, 0, n * size); + return ret; +} -- cgit v1.3.1