Messages in this thread | | | Subject | Re: [PATCH] fs: btrfs: Fix a possible null-pointer dereference in insert_inline_extent() | From | Qu Wenruo <> | Date | Wed, 24 Jul 2019 10:57:24 +0800 |
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On 2019/7/24 上午10:33, Jia-Ju Bai wrote: > > > On 2019/7/24 10:21, Qu Wenruo wrote: >> >> On 2019/7/24 上午10:11, Jia-Ju Bai wrote: >>> In insert_inline_extent(), there is an if statement on line 181 to check >>> whether compressed_pages is NULL: >>> if (compressed_size && compressed_pages) >>> >>> When compressed_pages is NULL, compressed_pages is used on line 215: >>> cpage = compressed_pages[i]; >>> >>> Thus, a possible null-pointer dereference may occur. >>> >>> To fix this possible bug, compressed_pages is checked on line 214. >> This can only be hit with compressed_size > 0 and compressed_pages != >> NULL. >> >> It would be better to have an extra ASSERT() to warn developers about >> the impossible case. > > Thanks for the reply :) > So I should add ASSERT(compressed_size > 0 & compressed_pages) at the > beginning of the function, and remove "if (compressed_size && > compressed_pages)"?
My suggestion is, ASSERT((compressed_size >0 && compressed_pages) || (compressed_size == 0 && !compressed_pages))
And keeps the original checks.
Anyway, just a suggestion.
Thanks, Qu
> > > Best wishes, > Jia-Ju Bai
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