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Yang Erkun 2530766492 nfsd: fix UAF when access ex_uuid or ex_stats
We can access exp->ex_stats or exp->ex_uuid in rcu context(c_show and
e_show). All these resources should be released using kfree_rcu. Fix this
by using call_rcu, clean them all after a rcu grace period.

==================================================================
BUG: KASAN: slab-use-after-free in svc_export_show+0x362/0x430 [nfsd]
Read of size 1 at addr ff11000010fdc120 by task cat/870

CPU: 1 UID: 0 PID: 870 Comm: cat Not tainted 6.12.0-rc3+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x53/0x70
 print_address_description.constprop.0+0x2c/0x3a0
 print_report+0xb9/0x280
 kasan_report+0xae/0xe0
 svc_export_show+0x362/0x430 [nfsd]
 c_show+0x161/0x390 [sunrpc]
 seq_read_iter+0x589/0x770
 seq_read+0x1e5/0x270
 proc_reg_read+0xe1/0x140
 vfs_read+0x125/0x530
 ksys_read+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Allocated by task 830:
 kasan_save_stack+0x20/0x40
 kasan_save_track+0x14/0x30
 __kasan_kmalloc+0x8f/0xa0
 __kmalloc_node_track_caller_noprof+0x1bc/0x400
 kmemdup_noprof+0x22/0x50
 svc_export_parse+0x8a9/0xb80 [nfsd]
 cache_do_downcall+0x71/0xa0 [sunrpc]
 cache_write_procfs+0x8e/0xd0 [sunrpc]
 proc_reg_write+0xe1/0x140
 vfs_write+0x1a5/0x6d0
 ksys_write+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 868:
 kasan_save_stack+0x20/0x40
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3b/0x60
 __kasan_slab_free+0x37/0x50
 kfree+0xf3/0x3e0
 svc_export_put+0x87/0xb0 [nfsd]
 cache_purge+0x17f/0x1f0 [sunrpc]
 nfsd_destroy_serv+0x226/0x2d0 [nfsd]
 nfsd_svc+0x125/0x1e0 [nfsd]
 write_threads+0x16a/0x2a0 [nfsd]
 nfsctl_transaction_write+0x74/0xa0 [nfsd]
 vfs_write+0x1a5/0x6d0
 ksys_write+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fixes: ae74136b4b ("SUNRPC: Allow cache lookups to use RCU protection rather than the r/w spinlock")
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-01-06 09:37:42 -05:00
Documentation 25 hotfixes. 16 are cc:stable. 18 are MM and 7 are non-MM. 2025-01-05 10:37:45 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
arch NIOS2: update for v6.14 2025-01-03 14:16:25 -08:00
block block: avoid to reuse `hctx` not removed from cpuhp callback list 2024-12-18 07:25:37 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: rsassa-pkcs1 - Copy source data for SG list 2024-12-10 13:34:05 +08:00
drivers A randconfig build fix and a performance fix: 2025-01-05 10:28:34 -08:00
fs nfsd: fix UAF when access ex_uuid or ex_stats 2025-01-06 09:37:42 -05:00
include SUNRPC: introduce cache_check_rcu to help check in rcu context 2025-01-06 09:37:40 -05:00
init - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
io_uring io_uring/kbuf: use pre-committed buffer address for non-pollable file 2025-01-03 09:38:37 -07:00
ipc - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
kernel 25 hotfixes. 16 are cc:stable. 18 are MM and 7 are non-MM. 2025-01-05 10:37:45 -08:00
lib maple_tree: reload mas before the second call for mas_empty_area 2024-12-30 17:59:07 -08:00
mm mm/util: make memdup_user_nul() similar to memdup_user() 2024-12-30 17:59:11 -08:00
net SUNRPC: no need get cache ref when protected by rcu 2025-01-06 09:37:41 -05:00
rust workqueue: Fixes for v6.13-rc5 2025-01-03 15:03:56 -08:00
samples BPF fixes: 2024-12-06 15:07:48 -08:00
scripts Kbuild fixes for v6.13 (3rd) 2025-01-05 10:52:47 -08:00
security selinux/stable-6.13 PR 20241217 2024-12-18 12:10:15 -08:00
sound sound fixes for 6.13-rc6 2025-01-03 10:54:51 -08:00
tools 25 hotfixes. 16 are cc:stable. 18 are MM and 7 are non-MM. 2025-01-05 10:37:45 -08:00
usr kbuild: Drop support for include/asm-<arch> in headers_check.pl 2024-12-21 11:43:17 +09:00
virt VFIO updates for v6.13 2024-11-27 12:57:03 -08:00
.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: enable Clippy's `check-private-items` 2024-10-07 21:39:57 +02:00
.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 updates for v6.13 2024-11-30 13:41:50 -08:00
.mailmap mailmap: modify the entry for Mathieu Othacehe 2024-12-30 17:59:08 -08:00
.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 cgroup: Changes for v6.13 2024-11-20 09:54:49 -08:00
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 25 hotfixes. 16 are cc:stable. 18 are MM and 7 are non-MM. 2025-01-05 10:37:45 -08:00
Makefile Linux 6.13-rc6 2025-01-05 14:13:40 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

README

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.