From d67ed2ccd2d1dcfda9292c0ea8697a9d0f2f0d98 Mon Sep 17 00:00:00 2001 From: Wang Jinchao Date: Thu, 12 Jun 2025 19:28:40 +0800 Subject: [PATCH 1/4] md/raid1: Fix stack memory use after return in raid1_reshape In the raid1_reshape function, newpool is allocated on the stack and assigned to conf->r1bio_pool. This results in conf->r1bio_pool.wait.head pointing to a stack address. Accessing this address later can lead to a kernel panic. Example access path: raid1_reshape() { // newpool is on the stack mempool_t newpool, oldpool; // initialize newpool.wait.head to stack address mempool_init(&newpool, ...); conf->r1bio_pool = newpool; } raid1_read_request() or raid1_write_request() { alloc_r1bio() { mempool_alloc() { // if pool->alloc fails remove_element() { --pool->curr_nr; } } } } mempool_free() { if (pool->curr_nr < pool->min_nr) { // pool->wait.head is a stack address // wake_up() will try to access this invalid address // which leads to a kernel panic return; wake_up(&pool->wait); } } Fix: reinit conf->r1bio_pool.wait after assigning newpool. Fixes: afeee514ce7f ("md: convert to bioset_init()/mempool_init()") Signed-off-by: Wang Jinchao Reviewed-by: Yu Kuai Link: https://lore.kernel.org/linux-raid/20250612112901.3023950-1-wangjinchao600@gmail.com Signed-off-by: Yu Kuai --- drivers/md/raid1.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 19c5a0ce5a40..fd4ce2a4136f 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -3428,6 +3428,7 @@ static int raid1_reshape(struct mddev *mddev) /* ok, everything is stopped */ oldpool = conf->r1bio_pool; conf->r1bio_pool = newpool; + init_waitqueue_head(&conf->r1bio_pool.wait); for (d = d2 = 0; d < conf->raid_disks; d++) { struct md_rdev *rdev = conf->mirrors[d].rdev; From 43806c3d5b9bb7d74ba4e33a6a8a41ac988bde24 Mon Sep 17 00:00:00 2001 From: Nigel Croxon Date: Thu, 3 Jul 2025 11:23:04 -0400 Subject: [PATCH 2/4] raid10: cleanup memleak at raid10_make_request If raid10_read_request or raid10_write_request registers a new request and the REQ_NOWAIT flag is set, the code does not free the malloc from the mempool. unreferenced object 0xffff8884802c3200 (size 192): comm "fio", pid 9197, jiffies 4298078271 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 88 41 02 00 00 00 00 00 .........A...... 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc c1a049a2): __kmalloc+0x2bb/0x450 mempool_alloc+0x11b/0x320 raid10_make_request+0x19e/0x650 [raid10] md_handle_request+0x3b3/0x9e0 __submit_bio+0x394/0x560 __submit_bio_noacct+0x145/0x530 submit_bio_noacct_nocheck+0x682/0x830 __blkdev_direct_IO_async+0x4dc/0x6b0 blkdev_read_iter+0x1e5/0x3b0 __io_read+0x230/0x1110 io_read+0x13/0x30 io_issue_sqe+0x134/0x1180 io_submit_sqes+0x48c/0xe90 __do_sys_io_uring_enter+0x574/0x8b0 do_syscall_64+0x5c/0xe0 entry_SYSCALL_64_after_hwframe+0x76/0x7e V4: changing backing tree to see if CKI tests will pass. The patch code has not changed between any versions. Fixes: c9aa889b035f ("md: raid10 add nowait support") Signed-off-by: Nigel Croxon Link: https://lore.kernel.org/linux-raid/c0787379-9caa-42f3-b5fc-369aed784400@redhat.com Signed-off-by: Yu Kuai --- drivers/md/raid10.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index b74780af4c22..917055dc01ed 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1182,8 +1182,11 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio, } } - if (!regular_request_wait(mddev, conf, bio, r10_bio->sectors)) + if (!regular_request_wait(mddev, conf, bio, r10_bio->sectors)) { + raid_end_bio_io(r10_bio); return; + } + rdev = read_balance(conf, r10_bio, &max_sectors); if (!rdev) { if (err_rdev) { @@ -1370,8 +1373,11 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, } sectors = r10_bio->sectors; - if (!regular_request_wait(mddev, conf, bio, sectors)) + if (!regular_request_wait(mddev, conf, bio, sectors)) { + raid_end_bio_io(r10_bio); return; + } + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && (mddev->reshape_backwards ? (bio->bi_iter.bi_sector < conf->reshape_safe && From 5fa31c49928139fa948f078b094d80f12ed83f5f Mon Sep 17 00:00:00 2001 From: Zheng Qixing Date: Wed, 2 Jul 2025 18:23:41 +0800 Subject: [PATCH 3/4] md/raid1,raid10: strip REQ_NOWAIT from member bios RAID layers don't implement proper non-blocking semantics for REQ_NOWAIT, making the flag potentially misleading when propagated to member disks. This patch clear REQ_NOWAIT from cloned bios in raid1/raid10. Retain original bio's REQ_NOWAIT flag for upper layer error handling. Maybe we can implement non-blocking I/O handling mechanisms within RAID in future work. Fixes: 9f346f7d4ea7 ("md/raid1,raid10: don't handle IO error for REQ_RAHEAD and REQ_NOWAIT") Signed-off-by: Zheng Qixing Link: https://lore.kernel.org/linux-raid/20250702102341.1969154-1-zhengqixing@huaweicloud.com Signed-off-by: Yu Kuai --- drivers/md/raid1.c | 3 ++- drivers/md/raid10.c | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index fd4ce2a4136f..64b8176907a9 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1399,7 +1399,7 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio, } read_bio = bio_alloc_clone(mirror->rdev->bdev, bio, gfp, &mddev->bio_set); - + read_bio->bi_opf &= ~REQ_NOWAIT; r1_bio->bios[rdisk] = read_bio; read_bio->bi_iter.bi_sector = r1_bio->sector + @@ -1649,6 +1649,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, wait_for_serialization(rdev, r1_bio); } + mbio->bi_opf &= ~REQ_NOWAIT; r1_bio->bios[i] = mbio; mbio->bi_iter.bi_sector = (r1_bio->sector + rdev->data_offset); diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 917055dc01ed..c9bd2005bfd0 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1224,6 +1224,7 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio, r10_bio->master_bio = bio; } read_bio = bio_alloc_clone(rdev->bdev, bio, gfp, &mddev->bio_set); + read_bio->bi_opf &= ~REQ_NOWAIT; r10_bio->devs[slot].bio = read_bio; r10_bio->devs[slot].rdev = rdev; @@ -1259,6 +1260,7 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio, conf->mirrors[devnum].rdev; mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO, &mddev->bio_set); + mbio->bi_opf &= ~REQ_NOWAIT; if (replacement) r10_bio->devs[n_copy].repl_bio = mbio; else From c17fb542dbd1db745c9feac15617056506dd7195 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?H=C3=A5kon=20Bugge?= Date: Wed, 2 Jul 2025 11:10:34 +0200 Subject: [PATCH 4/4] md/md-bitmap: fix GPF in bitmap_get_stats() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The commit message of commit 6ec1f0239485 ("md/md-bitmap: fix stats collection for external bitmaps") states: Remove the external bitmap check as the statistics should be available regardless of bitmap storage location. Return -EINVAL only for invalid bitmap with no storage (neither in superblock nor in external file). But, the code does not adhere to the above, as it does only check for a valid super-block for "internal" bitmaps. Hence, we observe: Oops: GPF, probably for non-canonical address 0x1cd66f1f40000028 RIP: 0010:bitmap_get_stats+0x45/0xd0 Call Trace: seq_read_iter+0x2b9/0x46a seq_read+0x12f/0x180 proc_reg_read+0x57/0xb0 vfs_read+0xf6/0x380 ksys_read+0x6d/0xf0 do_syscall_64+0x8c/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e We fix this by checking the existence of a super-block for both the internal and external case. Fixes: 6ec1f0239485 ("md/md-bitmap: fix stats collection for external bitmaps") Cc: stable@vger.kernel.org Reported-by: Gerald Gibson Signed-off-by: Håkon Bugge Link: https://lore.kernel.org/linux-raid/20250702091035.2061312-1-haakon.bugge@oracle.com Signed-off-by: Yu Kuai --- drivers/md/md-bitmap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index bd694910b01b..7f524a26cebc 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -2366,8 +2366,7 @@ static int bitmap_get_stats(void *data, struct md_bitmap_stats *stats) if (!bitmap) return -ENOENT; - if (!bitmap->mddev->bitmap_info.external && - !bitmap->storage.sb_page) + if (!bitmap->storage.sb_page) return -EINVAL; sb = kmap_local_page(bitmap->storage.sb_page); stats->sync_size = le64_to_cpu(sb->sync_size);