This is a note to let you know that I've just added the patch titled
erofs: fix wrong kunmap when using LZMA on HIGHMEM platforms
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
erofs-fix-wrong-kunmap-when-using-lzma-on-highmem-platforms.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8f121dfb15f7b4ab345992ce96003eb63fd608f4 Mon Sep 17 00:00:00 2001
From: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Date: Sun, 5 Mar 2023 21:44:55 +0800
Subject: erofs: fix wrong kunmap when using LZMA on HIGHMEM platforms
From: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
commit 8f121dfb15f7b4ab345992ce96003eb63fd608f4 upstream.
As the call trace shown, the root cause is kunmap incorrect pages:
BUG: kernel NULL pointer dereference, address: 00000000
CPU: 1 PID: 40 Comm: kworker/u5:0 Not tainted 6.2.0-rc5 #4
Workqueue: erofs_worker z_erofs_decompressqueue_work
EIP: z_erofs_lzma_decompress+0x34b/0x8ac
z_erofs_decompress+0x12/0x14
z_erofs_decompress_queue+0x7e7/0xb1c
z_erofs_decompressqueue_work+0x32/0x60
process_one_work+0x24b/0x4d8
? process_one_work+0x1a4/0x4d8
worker_thread+0x14c/0x3fc
kthread+0xe6/0x10c
? rescuer_thread+0x358/0x358
? kthread_complete_and_exit+0x18/0x18
ret_from_fork+0x1c/0x28
---[ end trace 0000000000000000 ]---
The bug is trivial and should be fixed now. It has no impact on
!HIGHMEM platforms.
Fixes: 622ceaddb764 ("erofs: lzma compression support")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.16+
Reviewed-by: Yue Hu <huyue2@xxxxxxxxxxx>
Reviewed-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230305134455.88236-1-hsiangkao@xxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/erofs/decompressor_lzma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/erofs/decompressor_lzma.c
+++ b/fs/erofs/decompressor_lzma.c
@@ -278,7 +278,7 @@ again:
}
}
if (no < nrpages_out && strm->buf.out)
- kunmap(rq->in[no]);
+ kunmap(rq->out[no]);
if (ni < nrpages_in)
kunmap(rq->in[ni]);
/* 4. push back LZMA stream context to the global list */
Patches currently in stable-queue which might be from hsiangkao@xxxxxxxxxxxxxxxxx are
queue-6.2/erofs-fix-wrong-kunmap-when-using-lzma-on-highmem-platforms.patch
