Messages in this thread | | | Subject | Re: [PATCH v2 3/5] f2fs: fix to avoid NULL pointer dereference | From | Chao Yu <> | Date | Thu, 26 Mar 2020 17:30:27 +0800 |
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Hi Jaegeuk,
I've made that diff as a patch and changed title and commit message a bit, let's merge the new one.
Thanks,
On 2020/3/25 23:50, Jaegeuk Kim wrote: > Hi Chao, > > I don't want to rebase old commit at this moment, so applied on top of the tree. > > Thanks, > > On 03/25, Chao Yu wrote: >> 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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