Messages in this thread | | | Subject | Re: [PATCH v5] f2fs: fix potential .flags overflow on 32bit architecture | From | Chao Yu <> | Date | Tue, 24 Mar 2020 14:13:28 +0800 |
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On 2020/3/23 23:10, Jaegeuk Kim wrote: > On 03/23, Joe Perches wrote: >> On Mon, 2020-03-23 at 11:18 +0800, Chao Yu wrote: >>> f2fs_inode_info.flags is unsigned long variable, it has 32 bits >>> in 32bit architecture, since we introduced FI_MMAP_FILE flag >>> when we support data compression, we may access memory cross >>> the border of .flags field, corrupting .i_sem field, result in >>> below deadlock. >> [] >>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >> [] >>> @@ -362,7 +362,7 @@ static int do_read_inode(struct inode *inode) >>> fi->i_flags = le32_to_cpu(ri->i_flags); >>> if (S_ISREG(inode->i_mode)) >>> fi->i_flags &= ~F2FS_PROJINHERIT_FL; >>> - fi->flags = 0; >>> + bitmap_zero(fi->flags, BITS_TO_LONGS(FI_MAX)); >> >> Sorry, I misled you here, this should be >> >> bitmap_zero(fi->flags, FI_MAX);
Oh, I missed to check that as well. :(
> > Thanks, I applied this directly in the f2fs tree.
Thanks for the help.
Thanks,
> . >
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