| Message ID | 20240902092459.5147-1-shivani.agarwal@broadcom.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v4.19-v5.10] block: initialize integrity buffer to zero before writing it to media | expand |
On Mon, Sep 02, 2024 at 02:24:59AM -0700, Shivani Agarwal wrote: > From: Christoph Hellwig <hch@lst.de> > > [ Upstream commit 899ee2c3829c5ac14bfc7d3c4a5846c0b709b78f ] > > Metadata added by bio_integrity_prep is using plain kmalloc, which leads > to random kernel memory being written media. For PI metadata this is > limited to the app tag that isn't used by kernel generated metadata, > but for non-PI metadata the entire buffer leaks kernel memory. > > Fix this by adding the __GFP_ZERO flag to allocations for writes. > > Fixes: 7ba1ba12eeef ("block: Block layer data integrity support") > Signed-off-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> > Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> > Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> > Link: https://lore.kernel.org/r/20240613084839.1044015-2-hch@lst.de > Signed-off-by: Jens Axboe <axboe@kernel.dk> > Signed-off-by: Sasha Levin <sashal@kernel.org> > Signed-off-by: Shivani Agarwal <shivani.agarwal@broadcom.com> > --- > block/bio-integrity.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) Now queued up, thanks. greg k-h
diff --git a/block/bio-integrity.c b/block/bio-integrity.c index a4cfc9727..499697330 100644 --- a/block/bio-integrity.c +++ b/block/bio-integrity.c @@ -216,6 +216,7 @@ bool bio_integrity_prep(struct bio *bio) unsigned int bytes, offset, i; unsigned int intervals; blk_status_t status; + gfp_t gfp = GFP_NOIO; if (!bi) return true; @@ -238,12 +239,20 @@ bool bio_integrity_prep(struct bio *bio) if (!bi->profile->generate_fn || !(bi->flags & BLK_INTEGRITY_GENERATE)) return true; + + /* + * Zero the memory allocated to not leak uninitialized kernel + * memory to disk. For PI this only affects the app tag, but + * for non-integrity metadata it affects the entire metadata + * buffer. + */ + gfp |= __GFP_ZERO; } intervals = bio_integrity_intervals(bi, bio_sectors(bio)); /* Allocate kernel buffer for protection data */ len = intervals * bi->tuple_size; - buf = kmalloc(len, GFP_NOIO | q->bounce_gfp); + buf = kmalloc(len, gfp | q->bounce_gfp); status = BLK_STS_RESOURCE; if (unlikely(buf == NULL)) { printk(KERN_ERR "could not allocate integrity buffer\n");