Messages in this thread | | | Subject | Re: [PATCH 4.19 33/75] f2fs: fix to avoid accessing xattr across the boundary | From | Chao Yu <> | Date | Thu, 20 Jun 2019 09:46:35 +0800 |
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Hi Pavel,
On 2019/6/19 20:32, Pavel Machek wrote: > Hi! > >> When we traverse xattr entries via __find_xattr(), >> if the raw filesystem content is faked or any hardware failure occurs, >> out-of-bound error can be detected by KASAN. >> Fix the issue by introducing boundary check. > > Ok, so this prevents fs corruption from causing problems, > >> @@ -340,7 +347,11 @@ static int lookup_all_xattrs(struct inode *inode, struct page *ipage, >> else >> cur_addr = txattr_addr; >> >> - *xe = __find_xattr(cur_addr, index, len, name); >> + *xe = __find_xattr(cur_addr, last_txattr_addr, index, len, name); >> + if (!*xe) { >> + err = -EFAULT; >> + goto out; >> + } > > Is -EFAULT suitable here? We do not have userspace passing pointers to us, we > have fs corruption. -EUNCLEAN?
Oh, right, f2fs uses -EFAULT as error number to indicate filesystem is corrupted all the time, we need to fix it to follow other generic fs.
> > Should it do some kind of printk to let the user know fs is corrupted, and mark > it as needing fsck?
Agreed, let me add it. :)
Thanks,
> > Thanks, > Pavel > . >
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