From: Christoph Hellwig hch@lst.de
stable inclusion from stable-v6.6.44 commit 23a19655fb56f241e592041156dfb1c6d04da644 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAKQ5R CVE: CVE-2024-43854
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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 Conflicts: block/bio-integrity.c [This is a conflict caused by commit ce288e053568("block: remove BLK_BOUNCE_ISA support") which is not merged.] Signed-off-by: Cheng Yu serein.chengyu@huawei.com --- block/bio-integrity.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/block/bio-integrity.c b/block/bio-integrity.c index 4f6f140a44e0..3473e0133468 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");