Messages in this thread Patch in this message | | | From | Chao Yu <> | Subject | [PATCH v2 3/5] f2fs: fix to avoid NULL pointer dereference | Date | Wed, 25 Mar 2020 17:18:11 +0800 |
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Unable to handle kernel NULL pointer dereference at virtual address 00000000 PC is at f2fs_free_dic+0x60/0x2c8 LR is at f2fs_decompress_pages+0x3c4/0x3e8 f2fs_free_dic+0x60/0x2c8 f2fs_decompress_pages+0x3c4/0x3e8 __read_end_io+0x78/0x19c f2fs_post_read_work+0x6c/0x94 process_one_work+0x210/0x48c worker_thread+0x2e8/0x44c kthread+0x110/0x120 ret_from_fork+0x10/0x18
In f2fs_free_dic(), we can not use f2fs_put_page(,1) to release dic->tpages[i], as the page's mapping is NULL.
Signed-off-by: Chao Yu <yuchao0@huawei.com> --- v2: - fix to skip release tpages[i] if it is NULL in error path. fs/f2fs/compress.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index ef7dd04312fe..6e10800729b6 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -1137,7 +1137,10 @@ void f2fs_free_dic(struct decompress_io_ctx *dic) for (i = 0; i < dic->cluster_size; i++) { if (dic->rpages[i]) continue; - f2fs_put_page(dic->tpages[i], 1); + if (!dic->tpages[i]) + continue; + unlock_page(dic->tpages[i]); + put_page(dic->tpages[i]); } kfree(dic->tpages); } -- 2.18.0.rc1
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