From: Alexander Potapenko <glider@google.com>
To: glider@google.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
Alexei Starovoitov <ast@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Andrey Konovalov <andreyknvl@google.com>,
Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Borislav Petkov <bp@alien8.de>, Christoph Hellwig <hch@lst.de>,
Christoph Lameter <cl@linux.com>,
David Rientjes <rientjes@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Eric Dumazet <edumazet@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
Ilya Leoshkevich <iii@linux.ibm.com>,
Ingo Molnar <mingo@redhat.com>, Jens Axboe <axboe@kernel.dk>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Kees Cook <keescook@chromium.org>,
Marco Elver <elver@google.com>,
Mark Rutland <mark.rutland@arm.com>,
Matthew Wilcox <willy@infradead.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Pekka Enberg <penberg@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
Vasily Gorbik <gor@linux.ibm.com>,
Vegard Nossum <vegard.nossum@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v4 44/45] mm: fs: initialize fsdata passed to write_begin/write_end interface
Date: Fri, 1 Jul 2022 16:23:09 +0200 [thread overview]
Message-ID: <20220701142310.2188015-45-glider@google.com> (raw)
In-Reply-To: <20220701142310.2188015-1-glider@google.com>
Functions implementing the a_ops->write_end() interface accept the
`void *fsdata` parameter that is supposed to be initialized by the
corresponding a_ops->write_begin() (which accepts `void **fsdata`).
However not all a_ops->write_begin() implementations initialize `fsdata`
unconditionally, so it may get passed uninitialized to a_ops->write_end(),
resulting in undefined behavior.
Fix this by initializing fsdata with NULL before the call to
write_begin(), rather than doing so in all possible a_ops
implementations.
This patch covers only the following cases found by running x86 KMSAN
under syzkaller:
- generic_perform_write()
- cont_expand_zero() and generic_cont_expand_simple()
- page_symlink()
Other cases of passing uninitialized fsdata may persist in the codebase.
Signed-off-by: Alexander Potapenko <glider@google.com>
---
Link: https://linux-review.googlesource.com/id/I414f0ee3a164c9c335d91d82ce4558f6f2841471
---
fs/buffer.c | 4 ++--
fs/namei.c | 2 +-
mm/filemap.c | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 898c7f301b1b9..d014009cff941 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2349,7 +2349,7 @@ int generic_cont_expand_simple(struct inode *inode, loff_t size)
struct address_space *mapping = inode->i_mapping;
const struct address_space_operations *aops = mapping->a_ops;
struct page *page;
- void *fsdata;
+ void *fsdata = NULL;
int err;
err = inode_newsize_ok(inode, size);
@@ -2375,7 +2375,7 @@ static int cont_expand_zero(struct file *file, struct address_space *mapping,
const struct address_space_operations *aops = mapping->a_ops;
unsigned int blocksize = i_blocksize(inode);
struct page *page;
- void *fsdata;
+ void *fsdata = NULL;
pgoff_t index, curidx;
loff_t curpos;
unsigned zerofrom, offset, len;
diff --git a/fs/namei.c b/fs/namei.c
index 6b39dfd3b41bc..5e3ff9d65f502 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -5051,7 +5051,7 @@ int page_symlink(struct inode *inode, const char *symname, int len)
const struct address_space_operations *aops = mapping->a_ops;
bool nofs = !mapping_gfp_constraint(mapping, __GFP_FS);
struct page *page;
- void *fsdata;
+ void *fsdata = NULL;
int err;
unsigned int flags;
diff --git a/mm/filemap.c b/mm/filemap.c
index ffdfbc8b0e3ca..72467f00f1916 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3753,7 +3753,7 @@ ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i)
unsigned long offset; /* Offset into pagecache page */
unsigned long bytes; /* Bytes to write to page */
size_t copied; /* Bytes copied from user */
- void *fsdata;
+ void *fsdata = NULL;
offset = (pos & (PAGE_SIZE - 1));
bytes = min_t(unsigned long, PAGE_SIZE - offset,
--
2.37.0.rc0.161.g10f37bed90-goog
next prev parent reply other threads:[~2022-07-01 14:25 UTC|newest]
Thread overview: 145+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-01 14:22 [PATCH v4 00/45] Add KernelMemorySanitizer infrastructure Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 01/45] x86: add missing include to sparsemem.h Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 02/45] stackdepot: reserve 5 extra bits in depot_stack_handle_t Alexander Potapenko
2022-07-12 14:17 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 03/45] instrumented.h: allow instrumenting both sides of copy_from_user() Alexander Potapenko
2022-07-12 14:17 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 04/45] x86: asm: instrument usercopy in get_user() and __put_user_size() Alexander Potapenko
2022-07-02 3:47 ` kernel test robot
2022-07-15 14:03 ` Alexander Potapenko
2022-07-02 10:45 ` kernel test robot
2022-07-15 16:44 ` Alexander Potapenko
2022-07-02 13:09 ` kernel test robot
2022-07-07 10:13 ` Marco Elver
2022-08-07 17:33 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 05/45] asm-generic: instrument usercopy in cacheflush.h Alexander Potapenko
2022-07-12 14:17 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 06/45] kmsan: add ReST documentation Alexander Potapenko
2022-07-07 12:34 ` Marco Elver
2022-07-15 7:42 ` Alexander Potapenko
2022-07-15 8:52 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 07/45] kmsan: introduce __no_sanitize_memory and __no_kmsan_checks Alexander Potapenko
2022-07-12 14:17 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 08/45] kmsan: mark noinstr as __no_sanitize_memory Alexander Potapenko
2022-07-12 14:17 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 09/45] x86: kmsan: pgtable: reduce vmalloc space Alexander Potapenko
2022-07-11 16:12 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 10/45] libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE Alexander Potapenko
2022-07-11 16:26 ` Marco Elver
2022-08-03 9:41 ` Alexander Potapenko
2022-08-03 9:44 ` Alexander Potapenko
2023-01-05 22:08 ` Dan Williams
2023-01-09 9:51 ` Alexander Potapenko
2023-01-09 22:06 ` Dan Williams
2023-01-10 5:56 ` Greg Kroah-Hartman
2023-01-10 6:55 ` Dan Williams
2023-01-10 8:48 ` Alexander Potapenko
2023-01-10 8:52 ` Alexander Potapenko
2023-01-10 8:53 ` Eric Dumazet
2023-01-10 8:55 ` Christoph Hellwig
2023-01-10 15:35 ` Steven Rostedt
2023-01-10 9:14 ` Alexander Potapenko
2023-01-30 8:34 ` Alexander Potapenko
2023-01-30 18:57 ` Dan Williams
2022-07-01 14:22 ` [PATCH v4 11/45] kmsan: add KMSAN runtime core Alexander Potapenko
2022-07-02 0:18 ` Hillf Danton
2022-08-03 17:25 ` Alexander Potapenko
2022-07-11 16:49 ` Marco Elver
2022-08-03 18:14 ` Alexander Potapenko
2022-07-13 10:04 ` Marco Elver
2022-08-03 17:45 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 12/45] kmsan: disable instrumentation of unsupported common kernel code Alexander Potapenko
2022-07-12 11:54 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 13/45] MAINTAINERS: add entry for KMSAN Alexander Potapenko
2022-07-12 12:06 ` Marco Elver
2022-08-02 16:39 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 14/45] mm: kmsan: maintain KMSAN metadata for page operations Alexander Potapenko
2022-07-12 12:20 ` Marco Elver
2022-08-03 10:30 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 15/45] mm: kmsan: call KMSAN hooks from SLUB code Alexander Potapenko
2022-07-12 13:13 ` Marco Elver
2022-08-02 16:31 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 16/45] kmsan: handle task creation and exiting Alexander Potapenko
2022-07-12 13:17 ` Marco Elver
2022-08-02 15:47 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 17/45] init: kmsan: call KMSAN initialization routines Alexander Potapenko
2022-07-12 14:05 ` Marco Elver
2022-08-02 20:07 ` Alexander Potapenko
2022-08-03 9:08 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 18/45] instrumented.h: add KMSAN support Alexander Potapenko
2022-07-12 13:51 ` Marco Elver
2022-08-03 11:17 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 19/45] kmsan: unpoison @tlb in arch_tlb_gather_mmu() Alexander Potapenko
2022-07-13 9:28 ` Marco Elver
2022-07-01 14:22 ` [PATCH v4 20/45] kmsan: add iomap support Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 21/45] Input: libps2: mark data received in __ps2_command() as initialized Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 22/45] dma: kmsan: unpoison DMA mappings Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 23/45] virtio: kmsan: check/unpoison scatterlist in vring_map_one_sg() Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 24/45] kmsan: handle memory sent to/from USB Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 25/45] kmsan: add tests for KMSAN Alexander Potapenko
2022-07-12 14:16 ` Marco Elver
2022-08-02 17:29 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 26/45] kmsan: disable strscpy() optimization under KMSAN Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 27/45] crypto: kmsan: disable accelerated configs " Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 28/45] kmsan: disable physical page merging in biovec Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 29/45] block: kmsan: skip bio block merging logic for KMSAN Alexander Potapenko
2022-07-13 10:22 ` Marco Elver
2022-08-02 17:47 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 30/45] kcov: kmsan: unpoison area->list in kcov_remote_area_put() Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 31/45] security: kmsan: fix interoperability with auto-initialization Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 32/45] objtool: kmsan: list KMSAN API functions as uaccess-safe Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 33/45] x86: kmsan: disable instrumentation of unsupported code Alexander Potapenko
2022-07-12 13:43 ` Marco Elver
2022-08-03 10:52 ` Alexander Potapenko
2022-07-01 14:22 ` [PATCH v4 34/45] x86: kmsan: skip shadow checks in __switch_to() Alexander Potapenko
2022-07-01 14:23 ` [PATCH v4 35/45] x86: kmsan: handle open-coded assembly in lib/iomem.c Alexander Potapenko
2022-07-01 14:23 ` [PATCH v4 36/45] x86: kmsan: use __msan_ string functions where possible Alexander Potapenko
2022-07-01 14:23 ` [PATCH v4 37/45] x86: kmsan: sync metadata pages on page fault Alexander Potapenko
2022-07-01 14:23 ` [PATCH v4 38/45] x86: kasan: kmsan: support CONFIG_GENERIC_CSUM on x86, enable it for KASAN/KMSAN Alexander Potapenko
2022-07-01 14:23 ` [PATCH v4 39/45] x86: fs: kmsan: disable CONFIG_DCACHE_WORD_ACCESS Alexander Potapenko
2022-07-01 14:23 ` [PATCH v4 40/45] x86: kmsan: don't instrument stack walking functions Alexander Potapenko
2022-07-01 14:23 ` [PATCH v4 41/45] entry: kmsan: introduce kmsan_unpoison_entry_regs() Alexander Potapenko
2022-07-01 14:23 ` [PATCH v4 42/45] bpf: kmsan: initialize BPF registers with zeroes Alexander Potapenko
2022-07-01 14:23 ` [PATCH v4 43/45] namei: initialize parameters passed to step_into() Alexander Potapenko
2022-07-02 17:23 ` Linus Torvalds
2022-07-03 3:59 ` Al Viro
2022-07-04 2:52 ` Al Viro
2022-07-04 8:20 ` Alexander Potapenko
2022-07-04 13:44 ` Al Viro
2022-07-04 13:55 ` Al Viro
2022-07-04 15:49 ` Alexander Potapenko
2022-07-04 16:03 ` Greg Kroah-Hartman
2022-07-04 16:33 ` Alexander Potapenko
2022-07-04 18:23 ` Segher Boessenkool
2022-07-04 16:00 ` Al Viro
2022-07-04 16:47 ` Alexander Potapenko
2022-07-04 17:36 ` Linus Torvalds
2022-07-04 19:02 ` Al Viro
2022-07-04 19:16 ` Linus Torvalds
2022-07-04 19:55 ` Al Viro
2022-07-04 20:24 ` Linus Torvalds
2022-07-04 20:46 ` Al Viro
2022-07-04 20:51 ` Linus Torvalds
2022-07-04 21:04 ` Al Viro
2022-07-04 23:13 ` [PATCH 1/7] __follow_mount_rcu(): verify that mount_lock remains unchanged Al Viro
2022-07-04 23:14 ` [PATCH 2/7] follow_dotdot{,_rcu}(): change calling conventions Al Viro
2022-07-04 23:14 ` [PATCH 3/7] namei: stash the sampled ->d_seq into nameidata Al Viro
2022-07-04 23:15 ` [PATCH 4/7] step_into(): lose inode argument Al Viro
2022-07-04 23:15 ` [PATCH 5/7] follow_dotdot{,_rcu}(): don't bother with inode Al Viro
2022-07-04 23:16 ` [PATCH 6/7] lookup_fast(): " Al Viro
2022-07-04 23:17 ` [PATCH 7/7] step_into(): move fetching ->d_inode past handle_mounts() Al Viro
2022-07-04 23:19 ` [PATCH 1/7] __follow_mount_rcu(): verify that mount_lock remains unchanged Al Viro
2022-07-05 0:06 ` Linus Torvalds
2022-07-05 3:48 ` Al Viro
2022-07-04 20:47 ` [PATCH v4 43/45] namei: initialize parameters passed to step_into() Linus Torvalds
2022-08-08 16:37 ` Alexander Potapenko
2022-07-01 14:23 ` Alexander Potapenko [this message]
2022-07-04 20:07 ` [PATCH v4 44/45] mm: fs: initialize fsdata passed to write_begin/write_end interface Matthew Wilcox
2022-07-04 20:30 ` Al Viro
2022-08-25 15:39 ` Alexander Potapenko
2022-08-25 16:33 ` Linus Torvalds
2022-08-25 21:57 ` Segher Boessenkool
2022-08-26 19:41 ` Linus Torvalds
2022-08-31 13:32 ` Alexander Potapenko
2022-08-25 22:13 ` Segher Boessenkool
2022-07-01 14:23 ` [PATCH v4 45/45] x86: kmsan: enable KMSAN builds for x86 Alexander Potapenko
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