Update Linux to v5.10.157
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.157.tar.xz
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: I7b30d9e98d8c465d6b44de8e7433b4a40b3289ba
diff --git a/fs/coredump.c b/fs/coredump.c
index c56a3bd..edbaf61 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -41,6 +41,7 @@
#include <linux/fs.h>
#include <linux/path.h>
#include <linux/timekeeping.h>
+#include <linux/elf.h>
#include <linux/uaccess.h>
#include <asm/mmu_context.h>
@@ -52,6 +53,9 @@
#include <trace/events/sched.h>
+static bool dump_vma_snapshot(struct coredump_params *cprm);
+static void free_vma_snapshot(struct coredump_params *cprm);
+
int core_uses_pid;
unsigned int core_pipe_limit;
char core_pattern[CORENAME_MAX_SIZE] = "core";
@@ -601,6 +605,7 @@
* by any locks.
*/
.mm_flags = mm->flags,
+ .vma_meta = NULL,
};
audit_core_dumps(siginfo->si_signo);
@@ -806,9 +811,13 @@
pr_info("Core dump to |%s disabled\n", cn.corename);
goto close_fail;
}
+ if (!dump_vma_snapshot(&cprm))
+ goto close_fail;
+
file_start_write(cprm.file);
core_dumped = binfmt->core_dump(&cprm);
file_end_write(cprm.file);
+ free_vma_snapshot(&cprm);
}
if (ispipe && core_pipe_limit)
wait_for_dump_helpers(cprm.file);
@@ -969,6 +978,8 @@
return false;
}
+#define DUMP_SIZE_MAYBE_ELFHDR_PLACEHOLDER 1
+
/*
* Decide how much of @vma's contents should be included in a core dump.
*/
@@ -1028,9 +1039,20 @@
* dump the first page to aid in determining what was mapped here.
*/
if (FILTER(ELF_HEADERS) &&
- vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ) &&
- (READ_ONCE(file_inode(vma->vm_file)->i_mode) & 0111) != 0)
- return PAGE_SIZE;
+ vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
+ if ((READ_ONCE(file_inode(vma->vm_file)->i_mode) & 0111) != 0)
+ return PAGE_SIZE;
+
+ /*
+ * ELF libraries aren't always executable.
+ * We'll want to check whether the mapping starts with the ELF
+ * magic, but not now - we're holding the mmap lock,
+ * so copy_from_user() doesn't work here.
+ * Use a placeholder instead, and fix it up later in
+ * dump_vma_snapshot().
+ */
+ return DUMP_SIZE_MAYBE_ELFHDR_PLACEHOLDER;
+ }
#undef FILTER
@@ -1067,18 +1089,29 @@
return gate_vma;
}
+static void free_vma_snapshot(struct coredump_params *cprm)
+{
+ if (cprm->vma_meta) {
+ int i;
+ for (i = 0; i < cprm->vma_count; i++) {
+ struct file *file = cprm->vma_meta[i].file;
+ if (file)
+ fput(file);
+ }
+ kvfree(cprm->vma_meta);
+ cprm->vma_meta = NULL;
+ }
+}
+
/*
* Under the mmap_lock, take a snapshot of relevant information about the task's
* VMAs.
*/
-int dump_vma_snapshot(struct coredump_params *cprm, int *vma_count,
- struct core_vma_metadata **vma_meta,
- size_t *vma_data_size_ptr)
+static bool dump_vma_snapshot(struct coredump_params *cprm)
{
struct vm_area_struct *vma, *gate_vma;
struct mm_struct *mm = current->mm;
int i;
- size_t vma_data_size = 0;
/*
* Once the stack expansion code is fixed to not change VMA bounds
@@ -1086,36 +1119,51 @@
* mmap_lock in read mode.
*/
if (mmap_write_lock_killable(mm))
- return -EINTR;
+ return false;
+ cprm->vma_data_size = 0;
gate_vma = get_gate_vma(mm);
- *vma_count = mm->map_count + (gate_vma ? 1 : 0);
+ cprm->vma_count = mm->map_count + (gate_vma ? 1 : 0);
- *vma_meta = kvmalloc_array(*vma_count, sizeof(**vma_meta), GFP_KERNEL);
- if (!*vma_meta) {
+ cprm->vma_meta = kvmalloc_array(cprm->vma_count, sizeof(*cprm->vma_meta), GFP_KERNEL);
+ if (!cprm->vma_meta) {
mmap_write_unlock(mm);
- return -ENOMEM;
+ return false;
}
for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
vma = next_vma(vma, gate_vma), i++) {
- struct core_vma_metadata *m = (*vma_meta) + i;
+ struct core_vma_metadata *m = cprm->vma_meta + i;
m->start = vma->vm_start;
m->end = vma->vm_end;
m->flags = vma->vm_flags;
m->dump_size = vma_dump_size(vma, cprm->mm_flags);
+ m->pgoff = vma->vm_pgoff;
- vma_data_size += m->dump_size;
+ m->file = vma->vm_file;
+ if (m->file)
+ get_file(m->file);
}
mmap_write_unlock(mm);
- if (WARN_ON(i != *vma_count)) {
- kvfree(*vma_meta);
- return -EFAULT;
+ for (i = 0; i < cprm->vma_count; i++) {
+ struct core_vma_metadata *m = cprm->vma_meta + i;
+
+ if (m->dump_size == DUMP_SIZE_MAYBE_ELFHDR_PLACEHOLDER) {
+ char elfmag[SELFMAG];
+
+ if (copy_from_user(elfmag, (void __user *)m->start, SELFMAG) ||
+ memcmp(elfmag, ELFMAG, SELFMAG) != 0) {
+ m->dump_size = 0;
+ } else {
+ m->dump_size = PAGE_SIZE;
+ }
+ }
+
+ cprm->vma_data_size += m->dump_size;
}
- *vma_data_size_ptr = vma_data_size;
- return 0;
+ return true;
}