kernel/linux.git/block/ioctl.c, branch v6.6.131

block: fix race between set_blocksize and read paths

2025-10-23T14:16:38+00:00

commit c0e473a0d226479e8e925d5ba93f751d8df628e9 upstream. With the new large sector size support, it's now the case that set_blocksize can change i_blksize and the folio order in a manner that conflicts with a concurrent reader and causes a kernel crash. Specifically, let's say that udev-worker calls libblkid to detect the labels on a block device. The read call can create an order-0 folio to read the first 4096 bytes from the disk. But then udev is preempted. Next, someone tries to mount an 8k-sectorsize filesystem from the same block device. The filesystem calls set_blksize, which sets i_blksize to 8192 and the minimum folio order to 1. Now udev resumes, still holding the order-0 folio it allocated. It then tries to schedule a read bio and do_mpage_readahead tries to create bufferheads for the folio. Unfortunately, blocks_per_folio == 0 because the page size is 4096 but the blocksize is 8192 so no bufferheads are attached and the bh walk never sets bdev. We then submit the bio with a NULL block device and crash. Therefore, truncate the page cache after flushing but before updating i_blksize. However, that's not enough -- we also need to lock out file IO and page faults during the update. Take both the i_rwsem and the invalidate_lock in exclusive mode for invalidations, and in shared mode for read/write operations. I don't know if this is the correct fix, but xfs/259 found it. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain Tested-by: Shin'ichiro Kawasaki Link: https://lore.kernel.org/r/174543795699.4139148.2086129139322431423.stgit@frogsfrogsfrogs Signed-off-by: Jens Axboe [ use bdev->bd_inode instead ] Signed-off-by: Mahmoud Adam Signed-off-by: Greg Kroah-Hartman

block: fix integer overflow in BLKSECDISCARD

2025-02-01T17:37:54+00:00

commit 697ba0b6ec4ae04afb67d3911799b5e2043b4455 upstream. I independently rediscovered commit 22d24a544b0d49bbcbd61c8c0eaf77d3c9297155 block: fix overflow in blk_ioctl_discard() but for secure erase. Same problem: uint64_t r[2] = {512, 18446744073709551104ULL}; ioctl(fd, BLKSECDISCARD, r); will enter near infinite loop inside blkdev_issue_secure_erase(): a.out: attempt to access beyond end of device loop0: rw=5, sector=3399043073, nr_sectors = 1024 limit=2048 bio_check_eod: 3286214 callbacks suppressed Signed-off-by: Alexey Dobriyan Link: https://lore.kernel.org/r/9e64057f-650a-46d1-b9f7-34af391536ef@p183 Signed-off-by: Jens Axboe Signed-off-by: Rajani Kantha Signed-off-by: Greg Kroah-Hartman

block/ioctl: prefer different overflow check

2024-06-27T11:49:01+00:00

[ Upstream commit ccb326b5f9e623eb7f130fbbf2505ec0e2dcaff9 ] Running syzkaller with the newly reintroduced signed integer overflow sanitizer shows this report: [ 62.982337] ------------[ cut here ]------------ [ 62.985692] cgroup: Invalid name [ 62.986211] UBSAN: signed-integer-overflow in ../block/ioctl.c:36:46 [ 62.989370] 9pnet_fd: p9_fd_create_tcp (7343): problem connecting socket to 127.0.0.1 [ 62.992992] 9223372036854775807 + 4095 cannot be represented in type 'long long' [ 62.997827] 9pnet_fd: p9_fd_create_tcp (7345): problem connecting socket to 127.0.0.1 [ 62.999369] random: crng reseeded on system resumption [ 63.000634] GUP no longer grows the stack in syz-executor.2 (7353): 20002000-20003000 (20001000) [ 63.000668] CPU: 0 PID: 7353 Comm: syz-executor.2 Not tainted 6.8.0-rc2-00035-gb3ef86b5a957 #1 [ 63.000677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 63.000682] Call Trace: [ 63.000686] [ 63.000731] dump_stack_lvl+0x93/0xd0 [ 63.000919] __get_user_pages+0x903/0xd30 [ 63.001030] __gup_longterm_locked+0x153e/0x1ba0 [ 63.001041] ? _raw_read_unlock_irqrestore+0x17/0x50 [ 63.001072] ? try_get_folio+0x29c/0x2d0 [ 63.001083] internal_get_user_pages_fast+0x1119/0x1530 [ 63.001109] iov_iter_extract_pages+0x23b/0x580 [ 63.001206] bio_iov_iter_get_pages+0x4de/0x1220 [ 63.001235] iomap_dio_bio_iter+0x9b6/0x1410 [ 63.001297] __iomap_dio_rw+0xab4/0x1810 [ 63.001316] iomap_dio_rw+0x45/0xa0 [ 63.001328] ext4_file_write_iter+0xdde/0x1390 [ 63.001372] vfs_write+0x599/0xbd0 [ 63.001394] ksys_write+0xc8/0x190 [ 63.001403] do_syscall_64+0xd4/0x1b0 [ 63.001421] ? arch_exit_to_user_mode_prepare+0x3a/0x60 [ 63.001479] entry_SYSCALL_64_after_hwframe+0x6f/0x77 [ 63.001535] RIP: 0033:0x7f7fd3ebf539 [ 63.001551] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 63.001562] RSP: 002b:00007f7fd32570c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 63.001584] RAX: ffffffffffffffda RBX: 00007f7fd3ff3f80 RCX: 00007f7fd3ebf539 [ 63.001590] RDX: 4db6d1e4f7e43360 RSI: 0000000020000000 RDI: 0000000000000004 [ 63.001595] RBP: 00007f7fd3f1e496 R08: 0000000000000000 R09: 0000000000000000 [ 63.001599] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 63.001604] R13: 0000000000000006 R14: 00007f7fd3ff3f80 R15: 00007ffd415ad2b8 ... [ 63.018142] ---[ end trace ]--- Historically, the signed integer overflow sanitizer did not work in the kernel due to its interaction with `-fwrapv` but this has since been changed [1] in the newest version of Clang; It was re-enabled in the kernel with Commit 557f8c582a9ba8ab ("ubsan: Reintroduce signed overflow sanitizer"). Let's rework this overflow checking logic to not actually perform an overflow during the check itself, thus avoiding the UBSAN splat. [1]: https://github.com/llvm/llvm-project/pull/82432 Signed-off-by: Justin Stitt Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240507-b4-sio-block-ioctl-v3-1-ba0c2b32275e@google.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: fix overflow in blk_ioctl_discard()

2024-05-17T10:02:13+00:00

[ Upstream commit 22d24a544b0d49bbcbd61c8c0eaf77d3c9297155 ] There is no check for overflow of 'start + len' in blk_ioctl_discard(). Hung task occurs if submit an discard ioctl with the following param: start = 0x80000000000ff000, len = 0x8000000000fff000; Add the overflow validation now. Signed-off-by: Li Nan Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240329012319.2034550-1-linan666@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: Move checking GENHD_FL_NO_PART to bdev_add_partition()

2024-02-01T00:19:12+00:00

[ Upstream commit 7777f47f2ea64efd1016262e7b59fab34adfb869 ] Commit 1a721de8489f ("block: don't add or resize partition on the disk with GENHD_FL_NO_PART") prevented all operations about partitions on disks with GENHD_FL_NO_PART in blkpg_do_ioctl() since they are meaningless. However, it changed error code in some scenarios. So move checking GENHD_FL_NO_PART to bdev_add_partition() to eliminate impact. Fixes: 1a721de8489f ("block: don't add or resize partition on the disk with GENHD_FL_NO_PART") Reported-by: Allison Karlitskaya Closes: https://lore.kernel.org/all/CAOYeF9VsmqKMcQjo1k6YkGNujwN-nzfxY17N3F-CMikE1tYp+w@mail.gmail.com/ Signed-off-by: Li Lingfeng Reviewed-by: Yu Kuai Link: https://lore.kernel.org/r/20240118130401.792757-1-lilingfeng@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: add check that partition length needs to be aligned with block size

2024-01-25T23:35:46+00:00

commit 6f64f866aa1ae6975c95d805ed51d7e9433a0016 upstream. Before calling add partition or resize partition, there is no check on whether the length is aligned with the logical block size. If the logical block size of the disk is larger than 512 bytes, then the partition size maybe not the multiple of the logical block size, and when the last sector is read, bio_truncate() will adjust the bio size, resulting in an IO error if the size of the read command is smaller than the logical block size.If integrity data is supported, this will also result in a null pointer dereference when calling bio_integrity_free. Cc: Signed-off-by: Min Li Reviewed-by: Damien Le Moal Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230629142517.121241-1-min15.li@samsung.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: don't add or resize partition on the disk with GENHD_FL_NO_PART

2023-08-31T14:00:35+00:00

Commit a33df75c6328 ("block: use an xarray for disk->part_tbl") remove disk_expand_part_tbl() in add_partition(), which means all kinds of devices will support extended dynamic `dev_t`. However, some devices with GENHD_FL_NO_PART are not expected to add or resize partition. Fix this by adding check of GENHD_FL_NO_PART before add or resize partition. Fixes: a33df75c6328 ("block: use an xarray for disk->part_tbl") Signed-off-by: Li Lingfeng Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230831075900.1725842-1-lilingfeng@huaweicloud.com Signed-off-by: Jens Axboe

block: call into the file system for ioctl BLKFLSBUF

2023-08-21T12:35:32+00:00

BLKFLSBUF is a historic ioctl that is called on a file handle to a block device and syncs either the file system mounted on that block device if there is one, or otherwise the just the data on the block device. Replace the get_super based syncing with a holder operation to remove the last usage of get_super, and to also support syncing the file system if the block device is not the main block device stored in s_dev. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Message-Id: <20230811100828.1897174-16-hch@lst.de> Signed-off-by: Christian Brauner

block: fine-granular CAP_SYS_ADMIN for Persistent Reservation

2023-06-20T18:49:23+00:00

Allow of unprivileged Persistent Reservation operations on devices if the write permission check on the device node has passed. brw-rw---- 1 root disk 259, 0 Jun 13 07:09 /dev/nvme0n1 In the example above, the "disk" group of nvme0n1 is also allowed to make reservations on the device even without CAP_SYS_ADMIN. Signed-off-by: Jingbo Xu Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230613084008.93795-3-jefflexu@linux.alibaba.com Signed-off-by: Jens Axboe

block: disallow Persistent Reservation on partitions

2023-06-20T18:49:23+00:00

Refuse Persistent Reservation operations on partitions as reservation on partitions doesn't make sense. Besides, introduce blkdev_pr_allowed() helper, where more policies could be placed here later. Signed-off-by: Jingbo Xu Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230613084008.93795-2-jefflexu@linux.alibaba.com Signed-off-by: Jens Axboe