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Justin Stitt 58706e482b 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>
2024-07-05 09:12:33 +02:00
arch powerpc/uaccess: Fix build errors seen with GCC 13/14 2024-07-05 09:12:26 +02:00
block block/ioctl: prefer different overflow check 2024-07-05 09:12:33 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:13:17 +02:00
crypto exit: Rename module_put_and_exit to module_put_and_kthread_exit 2024-06-21 14:53:29 +02:00
Documentation Documentation: Add missing documentation for EXPORT_OP flags 2024-06-21 14:54:15 +02:00
drivers i2c: designware: Fix the functionality flags of the slave-only interface 2024-07-05 09:12:33 +02:00
fs nilfs2: fix potential kernel bug due to lack of writeback flag waiting 2024-07-05 09:12:31 +02:00
include hugetlb_encode.h: fix undefined behaviour (34 << 26) 2024-07-05 09:12:32 +02:00
init init/main.c: Fix potential static_command_line memory overflow 2024-05-02 16:23:39 +02:00
io_uring io_uring: fail NOP if non-zero op flags is passed in 2024-06-16 13:32:30 +02:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:24:00 +01:00
kernel rcutorture: Fix invalid context warning when enable srcu barrier testing 2024-07-05 09:12:33 +02:00
lib dyndbg: fix old BUG_ON in >control parser 2024-05-17 11:48:10 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm fs: add file and path permissions helpers 2024-06-21 14:52:58 +02:00
net mptcp: pm: update add_addr counters after connect 2024-07-05 09:12:32 +02:00
samples samples/hw_breakpoint: fix building without module unloading 2023-09-23 11:01:09 +02:00
scripts kconfig: fix comparison to constant symbols, 'm', 'n' 2024-06-16 13:32:29 +02:00
security ima: fix deadlock when traversing "ima_default_rules". 2024-05-25 16:19:06 +02:00
sound ALSA: timer: Set lower bound of start tick time 2024-06-16 13:32:30 +02:00
tools hugetlb_encode.h: fix undefined behaviour (34 << 26) 2024-07-05 09:12:32 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-13 12:58:04 +02:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Remove DECnet support from kernel 2023-06-21 15:45:38 +02:00
Makefile Linux 5.10.220 2024-06-21 14:54:16 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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