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Sheng Yong 770c8d55c4 lib/iov_iter: fix to increase non slab folio refcount
When testing EROFS file-backed mount over v9fs on qemu, I encountered a
folio UAF issue.  The page sanity check reports the following call trace. 
The root cause is that pages in bvec are coalesced across a folio bounary.
The refcount of all non-slab folios should be increased to ensure
p9_releas_pages can put them correctly.

BUG: Bad page state in process md5sum  pfn:18300
page: refcount:0 mapcount:0 mapping:00000000d5ad8e4e index:0x60 pfn:0x18300
head: order:0 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
aops:z_erofs_aops ino:30b0f dentry name(?):"GoogleExtServicesCn.apk"
flags: 0x100000000000041(locked|head|node=0|zone=1)
raw: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0
raw: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000
head: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0
head: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000
head: 0100000000000000 0000000000000000 ffffffffffffffff 0000000000000000
head: 0000000000000010 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
Call Trace:
 dump_stack_lvl+0x53/0x70
 bad_page+0xd4/0x220
 __free_pages_ok+0x76d/0xf30
 __folio_put+0x230/0x320
 p9_release_pages+0x179/0x1f0
 p9_virtio_zc_request+0xa2a/0x1230
 p9_client_zc_rpc.constprop.0+0x247/0x700
 p9_client_read_once+0x34d/0x810
 p9_client_read+0xf3/0x150
 v9fs_issue_read+0x111/0x360
 netfs_unbuffered_read_iter_locked+0x927/0x1390
 netfs_unbuffered_read_iter+0xa2/0xe0
 vfs_iocb_iter_read+0x2c7/0x460
 erofs_fileio_rq_submit+0x46b/0x5b0
 z_erofs_runqueue+0x1203/0x21e0
 z_erofs_readahead+0x579/0x8b0
 read_pages+0x19f/0xa70
 page_cache_ra_order+0x4ad/0xb80
 filemap_readahead.isra.0+0xe7/0x150
 filemap_get_pages+0x7aa/0x1890
 filemap_read+0x320/0xc80
 vfs_read+0x6c6/0xa30
 ksys_read+0xf9/0x1c0
 do_syscall_64+0x9e/0x1a0
 entry_SYSCALL_64_after_hwframe+0x71/0x79

Link: https://lkml.kernel.org/r/20250401144712.1377719-1-shengyong1@xiaomi.com
Fixes: b9c0e49abf ("mm: decline to manipulate the refcount on a slab page")
Signed-off-by: Sheng Yong <shengyong1@xiaomi.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11 17:32:36 -07:00
arch A set of final cleanups for the timer subsystem: 2025-04-06 08:35:37 -07:00
block treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes reverts the multibuffer hash testing as it is buggy. 2025-04-02 09:14:59 -07:00
Documentation mseal: fix typo and style in documentation 2025-04-11 17:32:35 -07:00
drivers A set of final cleanups for the timer subsystem: 2025-04-06 08:35:37 -07:00
fs Miscellaneous scheduler fixes/updates: 2025-04-06 10:44:58 -07:00
include locking/local_lock, mm: replace localtry_ helpers with local_trylock_t type 2025-04-11 17:32:35 -07:00
init Miscellaneous scheduler fixes/updates: 2025-04-06 10:44:58 -07:00
io_uring io_uring: always do atomic put from iowq 2025-04-03 08:31:57 -06:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel Fix a perf events time accounting bug. 2025-04-06 10:48:12 -07:00
lib lib/iov_iter: fix to increase non slab folio refcount 2025-04-11 17:32:36 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm locking/local_lock, mm: replace localtry_ helpers with local_trylock_t type 2025-04-11 17:32:35 -07:00
net treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
rust Kbuild updates for v6.15 2025-04-05 15:46:50 -07:00
samples treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
scripts Disable SLUB_TINY for build testing 2025-04-06 10:00:04 -07:00
security mseal sysmap: kernel config and header change 2025-04-01 15:17:14 -07:00
sound soundwire fix for 6.15-rc1 2025-04-06 12:04:53 -07:00
tools test suite: use %zu to print size_t 2025-04-11 17:32:35 -07:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt ARM: 2025-03-25 14:22:07 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: Create intermediate vmlinux build with relocations preserved 2025-03-17 00:29:50 +09:00
.mailmap mailmap: map Loic Poulain's old email addresses 2025-04-11 17:32:34 -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 Including fixes from netfilter. 2025-04-04 09:15:35 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Kbuild updates for v6.15 2025-04-05 15:46:50 -07:00
Makefile Linux 6.15-rc1 2025-04-06 13:11:33 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.