From: Seth Jenkins sethjenkins@google.com
Commit 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") introduced a null-deref if there are no vma's in the task in show_smaps_rollup.
Fixes: 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") Cc: stable@vger.kernel.org Signed-off-by: Seth Jenkins sethjenkins@google.com --- fs/proc/task_mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 4e0023643f8b..1e7bbc0873a4 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -969,7 +969,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v) vma = vma->vm_next; }
- show_vma_header_prefix(m, priv->mm->mmap->vm_start, + show_vma_header_prefix(m, priv->mm->mmap ? priv->mm->mmap->vm_start : 0, last_vma_end, 0, 0, 0, 0); seq_pad(m, ' '); seq_puts(m, "[rollup]\n");
On Mon, Oct 03, 2022 at 06:45:31PM -0400, FirstName LastName wrote:
From: Seth Jenkins sethjenkins@google.com
Commit 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") introduced a null-deref if there are no vma's in the task in show_smaps_rollup.
Fixes: 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") Cc: stable@vger.kernel.org Signed-off-by: Seth Jenkins sethjenkins@google.com
--- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -969,7 +969,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v) vma = vma->vm_next; }
- show_vma_header_prefix(m, priv->mm->mmap->vm_start,
- show_vma_header_prefix(m, priv->mm->mmap ? priv->mm->mmap->vm_start : 0, last_vma_end, 0, 0, 0, 0); seq_pad(m, ' '); seq_puts(m, "[rollup]\n");
Reviewed-by: Alexey Dobriyan adobriyan@gmail.com Tested-by: Alexey Dobriyan adobriyan@gmail.com
Now I know how to create stable process without address space.
On Mon, 3 Oct 2022 18:45:31 -0400 FirstName LastName sethjenkins@google.com wrote:
From: Seth Jenkins sethjenkins@google.com
Commit 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") introduced a null-deref if there are no vma's in the task in show_smaps_rollup.
--- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -969,7 +969,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v) vma = vma->vm_next; }
- show_vma_header_prefix(m, priv->mm->mmap->vm_start,
- show_vma_header_prefix(m, priv->mm->mmap ? priv->mm->mmap->vm_start : 0, last_vma_end, 0, 0, 0, 0); seq_pad(m, ' '); seq_puts(m, "[rollup]\n");
The current mm tree is very different here. In fact the bug might not exist any more. Please take a look at the mm-stable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm?
If no fixes are needed in mm-stable then I guess the process is to propose this patch to the stable tree maintainers.
I concur, mm-stable looks fine to me as well.
Jann and I conversed today and the tentative decision since this isn't considered a high-priority security bug is to wait for maple tree to merge into Linus's branch before submitting this patch to stable.
On Tue, Oct 4, 2022 at 2:46 PM Andrew Morton akpm@linux-foundation.org wrote:
On Mon, 3 Oct 2022 18:45:31 -0400 FirstName LastName sethjenkins@google.com wrote:
From: Seth Jenkins sethjenkins@google.com
Commit 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") introduced a null-deref if there are no vma's in the task in show_smaps_rollup.
--- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -969,7 +969,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v) vma = vma->vm_next; }
show_vma_header_prefix(m, priv->mm->mmap->vm_start,
show_vma_header_prefix(m, priv->mm->mmap ? priv->mm->mmap->vm_start : 0, last_vma_end, 0, 0, 0, 0); seq_pad(m, ' '); seq_puts(m, "[rollup]\n");The current mm tree is very different here. In fact the bug might not exist any more. Please take a look at the mm-stable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm?
If no fixes are needed in mm-stable then I guess the process is to propose this patch to the stable tree maintainers.
linux-stable-mirror@lists.linaro.org
-
Alexey Dobriyan -
Andrew Morton -
FirstName LastName -
Seth Jenkins