The quilt patch titled
Subject: aio: fix mremap after fork null-deref
has been removed from the -mm tree. Its filename was
aio-fix-mremap-after-fork-null-deref.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
From: Seth Jenkins <sethjenkins@xxxxxxxxxx>
Subject: aio: fix mremap after fork null-deref
Date: Fri, 4 Nov 2022 17:25:19 -0400
Commit e4a0d3e720e7 ("aio: Make it possible to remap aio ring") introduced
a null-deref if mremap is called on an old aio mapping after fork as
mm->ioctx_table will be set to NULL.
Link: https://lkml.kernel.org/r/20221104212519.538108-1-sethjenkins@xxxxxxxxxx
Fixes: e4a0d3e720e7 ("aio: Make it possible to remap aio ring")
Signed-off-by: Seth Jenkins <sethjenkins@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Benjamin LaHaise <bcrl@xxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/aio.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
--- a/fs/aio.c~aio-fix-mremap-after-fork-null-deref
+++ a/fs/aio.c
@@ -361,16 +361,18 @@ static int aio_ring_mremap(struct vm_are
spin_lock(&mm->ioctx_lock);
rcu_read_lock();
table = rcu_dereference(mm->ioctx_table);
- for (i = 0; i < table->nr; i++) {
- struct kioctx *ctx;
+ if (table) {
+ for (i = 0; i < table->nr; i++) {
+ struct kioctx *ctx;
- ctx = rcu_dereference(table->table[i]);
- if (ctx && ctx->aio_ring_file == file) {
- if (!atomic_read(&ctx->dead)) {
- ctx->user_id = ctx->mmap_base = vma->vm_start;
- res = 0;
+ ctx = rcu_dereference(table->table[i]);
+ if (ctx && ctx->aio_ring_file == file) {
+ if (!atomic_read(&ctx->dead)) {
+ ctx->user_id = ctx->mmap_base = vma->vm_start;
+ res = 0;
+ }
+ break;
}
- break;
}
}
_
Patches currently in -mm which might be from sethjenkins@xxxxxxxxxx are
