Messages in this thread | | | Date | Sun, 23 Jul 2023 15:40:03 +0200 | From | Greg KH <> | Subject | Re: [PATCH v3] jfs: validate max amount of blocks before allocation. |
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On Sun, Jul 23, 2023 at 04:29:59PM +0300, Aleksei Filippov wrote: > From: Alexei Filippov <halip0503@gmail.com> > > The lack of checking bmp->db_max_freebud in extBalloc() can lead to > shift out of bounds, so this patch prevents undefined behavior, because > bmp->db_max_freebud == -1 only if there is no free space. > > Signed-off-by: Aleksei Filippov <halip0503@gmail.com> > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Reported-and-tested-by: syzbot+5f088f29593e6b4c8db8@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?id=01abadbd6ae6a08b1f1987aa61554c6b3ac19ff2 > --- > fs/jfs/jfs_extent.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/fs/jfs/jfs_extent.c b/fs/jfs/jfs_extent.c > index ae99a7e232ee..a82751e6c47f 100644 > --- a/fs/jfs/jfs_extent.c > +++ b/fs/jfs/jfs_extent.c > @@ -311,6 +311,11 @@ extBalloc(struct inode *ip, s64 hint, s64 * nblocks, s64 * blkno) > * blocks in the map. in that case, we'll start off with the > * maximum free. > */ > + > + /* give up if no space left */ > + if (bmp->db_maxfreebud == -1) > + return -ENOSPC; > + > max = (s64) 1 << bmp->db_maxfreebud; > if (*nblocks >= max && *nblocks > nbperpage) > nb = nblks = (max > nbperpage) ? max : nbperpage; > -- > 2.25.1 > > Fix commit message.
The --- information for the version goes below the first --- line, not the last. Look at the examples on the mailing lists for the proper format.
thanks,
greg k-h
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