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Diffstat (limited to 'fs/binfmt_elf.c')
-rw-r--r--fs/binfmt_elf.c51
1 files changed, 48 insertions, 3 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 7cb28720f90e..669dbe5b0317 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -682,6 +682,15 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
retval = PTR_ERR(interpreter);
if (IS_ERR(interpreter))
goto out_free_interp;
+
+ /*
+ * If the binary is not readable then enforce
+ * mm->dumpable = 0 regardless of the interpreter's
+ * permissions.
+ */
+ if (file_permission(interpreter, MAY_READ) < 0)
+ bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
+
retval = kernel_read(interpreter, 0, bprm->buf,
BINPRM_BUF_SIZE);
if (retval != BINPRM_BUF_SIZE) {
@@ -1178,6 +1187,10 @@ static int dump_seek(struct file *file, loff_t off)
*/
static int maydump(struct vm_area_struct *vma)
{
+ /* The vma can be set up to tell us the answer directly. */
+ if (vma->vm_flags & VM_ALWAYSDUMP)
+ return 1;
+
/* Do not dump I/O mapped devices or special mappings */
if (vma->vm_flags & (VM_IO | VM_RESERVED))
return 0;
@@ -1424,6 +1437,32 @@ static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
return sz;
}
+static struct vm_area_struct *first_vma(struct task_struct *tsk,
+ struct vm_area_struct *gate_vma)
+{
+ struct vm_area_struct *ret = tsk->mm->mmap;
+
+ if (ret)
+ return ret;
+ return gate_vma;
+}
+/*
+ * Helper function for iterating across a vma list. It ensures that the caller
+ * will visit `gate_vma' prior to terminating the search.
+ */
+static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
+ struct vm_area_struct *gate_vma)
+{
+ struct vm_area_struct *ret;
+
+ ret = this_vma->vm_next;
+ if (ret)
+ return ret;
+ if (this_vma == gate_vma)
+ return NULL;
+ return gate_vma;
+}
+
/*
* Actual dumper
*
@@ -1439,7 +1478,7 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
int segs;
size_t size = 0;
int i;
- struct vm_area_struct *vma;
+ struct vm_area_struct *vma, *gate_vma;
struct elfhdr *elf = NULL;
loff_t offset = 0, dataoff, foffset;
unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
@@ -1525,6 +1564,10 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
segs += ELF_CORE_EXTRA_PHDRS;
#endif
+ gate_vma = get_gate_vma(current);
+ if (gate_vma != NULL)
+ segs++;
+
/* Set up header */
fill_elf_header(elf, segs + 1); /* including notes section */
@@ -1592,7 +1635,8 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
/* Write program headers for segments dump */
- for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
+ for (vma = first_vma(current, gate_vma); vma != NULL;
+ vma = next_vma(vma, gate_vma)) {
struct elf_phdr phdr;
size_t sz;
@@ -1641,7 +1685,8 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
/* Align to page */
DUMP_SEEK(dataoff - foffset);
- for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
+ for (vma = first_vma(current, gate_vma); vma != NULL;
+ vma = next_vma(vma, gate_vma)) {
unsigned long addr;
if (!maydump(vma))