6.15-stable review patch. If anyone has any objections, please let me know.
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From: Pankaj Raghav p.raghav@samsung.com
[ Upstream commit 4cdf1bdd45ac78a088773722f009883af30ad318 ]
If THP is disabled and when a block device with logical block size > page size is present, the following null ptr deref panic happens during boot:
[ [13.2 mK AOSAN: null-ptr-deref in range [0x0000000000000000-0x0000000000K0 0 0[07] [ 13.017749] RIP: 0010:create_empty_buffers+0x3b/0x380 <snip> [ 13.025448] Call Trace: [ 13.025692] <TASK> [ 13.025895] block_read_full_folio+0x610/0x780 [ 13.026379] ? __pfx_blkdev_get_block+0x10/0x10 [ 13.027008] ? __folio_batch_add_and_move+0x1fa/0x2b0 [ 13.027548] ? __pfx_blkdev_read_folio+0x10/0x10 [ 13.028080] filemap_read_folio+0x9b/0x200 [ 13.028526] ? __pfx_filemap_read_folio+0x10/0x10 [ 13.029030] ? __filemap_get_folio+0x43/0x620 [ 13.029497] do_read_cache_folio+0x155/0x3b0 [ 13.029962] ? __pfx_blkdev_read_folio+0x10/0x10 [ 13.030381] read_part_sector+0xb7/0x2a0 [ 13.030805] read_lba+0x174/0x2c0 <snip> [ 13.045348] nvme_scan_ns+0x684/0x850 [nvme_core] [ 13.045858] ? __pfx_nvme_scan_ns+0x10/0x10 [nvme_core] [ 13.046414] ? _raw_spin_unlock+0x15/0x40 [ 13.046843] ? __switch_to+0x523/0x10a0 [ 13.047253] ? kvm_clock_get_cycles+0x14/0x30 [ 13.047742] ? __pfx_nvme_scan_ns_async+0x10/0x10 [nvme_core] [ 13.048353] async_run_entry_fn+0x96/0x4f0 [ 13.048787] process_one_work+0x667/0x10a0 [ 13.049219] worker_thread+0x63c/0xf60
As large folio support depends on THP, only allow bs > ps block devices if THP is enabled.
Fixes: 47dd67532303 ("block/bdev: lift block size restrictions to 64k") Signed-off-by: Pankaj Raghav p.raghav@samsung.com Reviewed-by: Luis Chamberlain mcgrof@kernel.org Link: https://lore.kernel.org/r/20250704092134.289491-1-p.raghav@samsung.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/blkdev.h | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 9a1f0ee40b566..7c2a66995518a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -268,11 +268,16 @@ static inline dev_t disk_devt(struct gendisk *disk) return MKDEV(disk->major, disk->first_minor); }
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE /* * We should strive for 1 << (PAGE_SHIFT + MAX_PAGECACHE_ORDER) * however we constrain this to what we can validate and test. */ #define BLK_MAX_BLOCK_SIZE SZ_64K +#else +#define BLK_MAX_BLOCK_SIZE PAGE_SIZE +#endif +
/* blk_validate_limits() validates bsize, so drivers don't usually need to */ static inline int blk_validate_block_size(unsigned long bsize)