kernel/linux.git/fs/isofs/export.c, branch v6.6.131

isofs: Prevent the use of too small fid

2025-04-25T08:45:48+00:00

commit 0405d4b63d082861f4eaff9d39c78ee9dc34f845 upstream. syzbot reported a slab-out-of-bounds Read in isofs_fh_to_parent. [1] The handle_bytes value passed in by the reproducing program is equal to 12. In handle_to_path(), only 12 bytes of memory are allocated for the structure file_handle->f_handle member, which causes an out-of-bounds access when accessing the member parent_block of the structure isofs_fid in isofs, because accessing parent_block requires at least 16 bytes of f_handle. Here, fh_len is used to indirectly confirm that the value of handle_bytes is greater than 3 before accessing parent_block. [1] BUG: KASAN: slab-out-of-bounds in isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183 Read of size 4 at addr ffff0000cc030d94 by task syz-executor215/6466 CPU: 1 UID: 0 PID: 6466 Comm: syz-executor215 Not tainted 6.14.0-rc7-syzkaller-ga2392f333575 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x198/0x550 mm/kasan/report.c:521 kasan_report+0xd8/0x138 mm/kasan/report.c:634 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380 isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183 exportfs_decode_fh_raw+0x2dc/0x608 fs/exportfs/expfs.c:523 do_handle_to_path+0xa0/0x198 fs/fhandle.c:257 handle_to_path fs/fhandle.c:385 [inline] do_handle_open+0x8cc/0xb8c fs/fhandle.c:403 __do_sys_open_by_handle_at fs/fhandle.c:443 [inline] __se_sys_open_by_handle_at fs/fhandle.c:434 [inline] __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Allocated by task 6466: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:562 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4294 [inline] __kmalloc_noprof+0x32c/0x54c mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] handle_to_path fs/fhandle.c:357 [inline] do_handle_open+0x5a4/0xb8c fs/fhandle.c:403 __do_sys_open_by_handle_at fs/fhandle.c:443 [inline] __se_sys_open_by_handle_at fs/fhandle.c:434 [inline] __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Reported-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4d7cd7dd0ce1aa8d5c65 Tested-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com CC: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Edward Adam Davis Signed-off-by: Jan Kara Link: https://patch.msgid.link/tencent_9C8CB8A7E7C6C512C7065DC98B6EDF6EC606@qq.com Signed-off-by: Greg Kroah-Hartman

docs: fs: convert docs without extension to ReST

2019-07-31T19:31:05+00:00

There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Jonathan Corbet

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

VFS: normal filesystems (and lustre): d_inode() annotations

2015-04-15T19:06:57+00:00

that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells Signed-off-by: Al Viro

fs: encode_fh: return FILEID_INVALID if invalid fid_type

2013-02-26T07:46:10+00:00

This patch is a follow up on below patch: [PATCH] exportfs: add FILEID_INVALID to indicate invalid fid_type commit: 216b6cbdcbd86b1db0754d58886b466ae31f5a63 Signed-off-by: Namjae Jeon Signed-off-by: Vivek Trivedi Acked-by: Steven Whitehouse Acked-by: Sage Weil Signed-off-by: Al Viro

tmpfs,ceph,gfs2,isofs,reiserfs,xfs: fix fh_len checking

2012-10-10T03:33:55+00:00

Fuzzing with trinity oopsed on the 1st instruction of shmem_fh_to_dentry(), u64 inum = fid->raw[2]; which is unhelpfully reported as at the end of shmem_alloc_inode(): BUG: unable to handle kernel paging request at ffff880061cd3000 IP: [] shmem_alloc_inode+0x40/0x40 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Call Trace: [] ? exportfs_decode_fh+0x79/0x2d0 [] do_handle_open+0x163/0x2c0 [] sys_open_by_handle_at+0xc/0x10 [] tracesys+0xe1/0xe6 Right, tmpfs is being stupid to access fid->raw[2] before validating that fh_len includes it: the buffer kmalloc'ed by do_sys_name_to_handle() may fall at the end of a page, and the next page not be present. But some other filesystems (ceph, gfs2, isofs, reiserfs, xfs) are being careless about fh_len too, in fh_to_dentry() and/or fh_to_parent(), and could oops in the same way: add the missing fh_len checks to those. Reported-by: Sasha Levin Signed-off-by: Hugh Dickins Cc: Al Viro Cc: Sage Weil Cc: Steven Whitehouse Cc: Christoph Hellwig Cc: stable@vger.kernel.org Signed-off-by: Al Viro

isofs: avoid info leak on export

2012-07-13T09:21:21+00:00

For type 1 the parent_offset member in struct isofs_fid gets copied uninitialized to userland. Fix this by initializing it to 0. Signed-off-by: Mathias Krause Signed-off-by: Jan Kara

->encode_fh() API change

2012-05-30T03:28:33+00:00

pass inode + parent's inode or NULL instead of dentry + bool saying whether we want the parent or not. NOTE: that needs ceph fix folded in. Signed-off-by: Al Viro

exportfs: Return the minimum required handle size

2011-03-14T13:15:28+00:00

The exportfs encode handle function should return the minimum required handle size. This helps user to find out the handle size by passing 0 handle size in the first step and then redoing to the call again with the returned handle size value. Acked-by: Serge Hallyn Signed-off-by: Aneesh Kumar K.V Signed-off-by: Al Viro

nfs: new subdir Documentation/filesystems/nfs

2009-10-27T23:34:04+00:00

We're adding enough nfs documentation that it may as well have its own subdirectory. Acked-by: Randy Dunlap Signed-off-by: J. Bruce Fields