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Justin Stitt ccb326b5f9 block/ioctl: prefer different overflow check
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 557f8c582a ("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>
2024-05-07 07:29:20 -06:00
arch Kbuild fixes for v6.9 2024-03-31 11:23:51 -07:00
block block/ioctl: prefer different overflow check 2024-05-07 07:29:20 -06:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression that broke iwd as well as a divide by 2024-03-25 10:48:23 -07:00
Documentation block: add a partscan sysfs attribute for disks 2024-05-03 09:00:07 -06:00
drivers null_blk: Fix the WARNING: modpost: missing MODULE_DESCRIPTION() 2024-05-06 06:50:09 -06:00
fs btrfs use bio_list_merge_init 2024-04-01 11:53:37 -06:00
include block: add a disk_has_partscan helper 2024-05-03 08:59:59 -06:00
init init: open /initrd.image with O_LARGEFILE 2024-03-26 11:07:19 -07:00
io_uring io_uring/sqpoll: early exit thread if task_context wasn't allocated 2024-03-18 20:22:42 -06:00
ipc sysctl changes for v6.9-rc1 2024-03-18 14:59:13 -07:00
kernel Kbuild fixes for v6.9 2024-03-31 11:23:51 -07:00
lib sbitmap: use READ_ONCE to access map->word 2024-04-26 07:40:28 -06:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm Kbuild fixes for v6.9 2024-03-31 11:23:51 -07:00
net nfsd-6.9 fixes: 2024-03-28 14:35:32 -07:00
rust Kbuild updates for v6.9 2024-03-21 14:41:00 -07:00
samples Tracing updates for 6.9: 2024-03-18 15:11:44 -07:00
scripts Kbuild fixes for v6.9 2024-03-31 11:23:51 -07:00
security - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min 2024-03-14 18:03:09 -07:00
sound sound fixes for 6.9-rc2 2024-03-28 14:54:49 -07:00
tools objtool: Fix compile failure when using the x32 compiler 2024-03-30 22:12:37 +01:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM Xen and pfncache changes for 6.9: 2024-03-11 10:42:55 -04:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap Including fixes from bpf, WiFi and netfilter. 2024-03-28 13:09:37 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Not a ton of stuff happening in the clk framework in this pull request. We got 2024-03-15 11:48:01 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS - Volunteer in Anna-Maria and Frederic as timers co-maintainers 2024-03-31 10:34:49 -07:00
Makefile Linux 6.9-rc2 2024-03-31 14:32:39 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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