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Check for the program headers alignment of the ELF images before

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dereferencing. Unaligned access could cause panic on strict alignment
architectures.

Reviewed by:	marcel, marius (also tested on sparc64, thanks !)
MFC after:	3 days
This commit is contained in:
kib 2007-12-04 12:21:27 +00:00
parent e957a260c9
commit dbef1afd93
1 changed files with 10 additions and 3 deletions
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13
sys/kern/imgact_elf.c
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@ -106,6 +106,10 @@ SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW,
static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
#define trunc_page_ps(va, ps) ((va) & ~(ps - 1))
#define round_page_ps(va, ps) (((va) + (ps - 1)) & ~(ps - 1))
#define aligned(a, t) (trunc_page_ps((u_long)(a), sizeof(t)) == (u_long)(a))
int
__elfN(insert_brand_entry)(Elf_Brandinfo *entry)
{
@ -360,9 +364,6 @@ __elfN(load_section)(struct vmspace *vmspace,
return (ENOEXEC);
}
#define trunc_page_ps(va, ps) ((va) & ~(ps - 1))
#define round_page_ps(va, ps) (((va) + (ps - 1)) & ~(ps - 1))
map_addr = trunc_page_ps((vm_offset_t)vmaddr, pagesize);
file_addr = trunc_page_ps(offset, pagesize);
@ -549,6 +550,10 @@ __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
}
phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
if (!aligned(phdr, Elf_Addr)) {
error = ENOEXEC;
goto fail;
}
for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
if (phdr[i].p_type == PT_LOAD) { /* Loadable segment */
@ -632,6 +637,8 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
return (ENOEXEC);
}
phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
if (!aligned(phdr, Elf_Addr))
return (ENOEXEC);
for (i = 0; i < hdr->e_phnum; i++) {
if (phdr[i].p_type == PT_INTERP) {
/* Path to interpreter */