Justin Stitt bf03d87826 block/ioctl: prefer different overflow check ... [ 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] <TASK> [ 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 <justinstitt@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20240507-b4-sio-block-ioctl-v3-1-ba0c2b32275e@google.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-11-19 14:19:06 +01:00
..
partitions
badblocks.c
bfq-cgroup.c
bfq-iosched.c
bfq-iosched.h
bfq-wf2q.c
bio-integrity.c
bio.c
blk-cgroup-rwstat.c
blk-cgroup-rwstat.h
blk-cgroup.c
blk-core.c
blk-crypto-fallback.c
blk-crypto-internal.h
blk-crypto.c
blk-exec.c
blk-flush.c
blk-integrity.c
blk-ioc.c
blk-iocost.c	blk-iocost: avoid out of bounds shift	2024-11-19 11:32:44 +01:00
blk-iolatency.c
blk-ioprio.c
blk-ioprio.h
blk-lib.c
blk-map.c
blk-merge.c
blk-mq-cpumap.c
blk-mq-debugfs-zoned.c
blk-mq-debugfs.c
blk-mq-debugfs.h
blk-mq-pci.c
blk-mq-rdma.c
blk-mq-sched.c
blk-mq-sched.h
blk-mq-sysfs.c
blk-mq-tag.c
blk-mq-tag.h
blk-mq-virtio.c
blk-mq.c
blk-mq.h
blk-pm.c
blk-pm.h
blk-rq-qos.c
blk-rq-qos.h
blk-sec-stats.c
blk-settings.c	block: Clear zone limits for a non-zoned stacked queue	2024-11-19 09:22:16 +01:00
blk-stat.c	block: prevent division by zero in blk_rq_stat_sum()	2024-11-19 09:23:14 +01:00
blk-stat.h
blk-sysfs.c
blk-throttle.c
blk-timeout.c
blk-wbt.c
blk-wbt.h
blk-zoned.c
blk.h
bounce.c
bsg-lib.c
bsg.c
cmdline-parser.c
elevator.c
genhd.c
ioctl.c	block/ioctl: prefer different overflow check	2024-11-19 14:19:06 +01:00
ioprio.c
Kconfig
Kconfig.iosched
keyslot-manager.c
kyber-iosched.c
Makefile
mq-deadline-cgroup.c
mq-deadline-cgroup.h
mq-deadline-main.c
opal_proto.h
scsi_ioctl.c
sed-opal.c
ssg-cgroup.c
ssg-cgroup.h
ssg-iosched.c
t10-pi.c