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* Merge tag 'pull-stable-struct_fd' of ↵Linus Torvalds2024-09-231-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.
| * introduce fd_file(), convert all accessors to it.Al Viro2024-08-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For any changes of struct fd representation we need to turn existing accesses to fields into calls of wrappers. Accesses to struct fd::flags are very few (3 in linux/file.h, 1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in explicit initializers). Those can be dealt with in the commit converting to new layout; accesses to struct fd::file are too many for that. This commit converts (almost) all of f.file to fd_file(f). It's not entirely mechanical ('file' is used as a member name more than just in struct fd) and it does not even attempt to distinguish the uses in pointer context from those in boolean context; the latter will be eventually turned into a separate helper (fd_empty()). NOTE: mass conversion to fd_empty(), tempting as it might be, is a bad idea; better do that piecewise in commit that convert from fdget...() to CLASS(...). [conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c caught by git; fs/stat.c one got caught by git grep] [fs/xattr.c conflict] Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | fhandle: expose u64 mount id to name_to_handle_at(2)Aleksa Sarai2024-09-051-7/+22
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we provide a unique 64-bit mount ID interface in statx(2), we can now provide a race-free way for name_to_handle_at(2) to provide a file handle and corresponding mount without needing to worry about racing with /proc/mountinfo parsing or having to open a file just to do statx(2). While this is not necessary if you are using AT_EMPTY_PATH and don't care about an extra statx(2) call, users that pass full paths into name_to_handle_at(2) need to know which mount the file handle comes from (to make sure they don't try to open_by_handle_at a file handle from a different filesystem) and switching to AT_EMPTY_PATH would require allocating a file for every name_to_handle_at(2) call, turning err = name_to_handle_at(-EBADF, "/foo/bar/baz", &handle, &mntid, AT_HANDLE_MNT_ID_UNIQUE); into int fd = openat(-EBADF, "/foo/bar/baz", O_PATH | O_CLOEXEC); err1 = name_to_handle_at(fd, "", &handle, &unused_mntid, AT_EMPTY_PATH); err2 = statx(fd, "", AT_EMPTY_PATH, STATX_MNT_ID_UNIQUE, &statxbuf); mntid = statxbuf.stx_mnt_id; close(fd); Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Link: https://lore.kernel.org/r/20240828-exportfs-u64-mount-id-v3-2-10c2c4c16708@cyphar.com Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
* fhandle: relax open_by_handle_at() permission checksChristian Brauner2024-05-281-38/+140
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A current limitation of open_by_handle_at() is that it's currently not possible to use it from within containers at all because we require CAP_DAC_READ_SEARCH in the initial namespace. That's unfortunate because there are scenarios where using open_by_handle_at() from within containers. Two examples: (1) cgroupfs allows to encode cgroups to file handles and reopen them with open_by_handle_at(). (2) Fanotify allows placing filesystem watches they currently aren't usable in containers because the returned file handles cannot be used. Here's a proposal for relaxing the permission check for open_by_handle_at(). (1) Opening file handles when the caller has privileges over the filesystem (1.1) The caller has an unobstructed view of the filesystem. (1.2) The caller has permissions to follow a path to the file handle. This doesn't address the problem of opening a file handle when only a portion of a filesystem is exposed as is common in containers by e.g., bind-mounting a subtree. The proposal to solve this use-case is: (2) Opening file handles when the caller has privileges over a subtree (2.1) The caller is able to reach the file from the provided mount fd. (2.2) The caller has permissions to construct an unobstructed path to the file handle. (2.3) The caller has permissions to follow a path to the file handle. The relaxed permission checks are currently restricted to directory file handles which are what both cgroupfs and fanotify need. Handling disconnected non-directory file handles would lead to a potentially non-deterministic api. If a disconnected non-directory file handle is provided we may fail to decode a valid path that we could use for permission checking. That in itself isn't a problem as we would just return EACCES in that case. However, confusion may arise if a non-disconnected dentry ends up in the cache later and those opening the file handle would suddenly succeed. * It's potentially possible to use timing information (side-channel) to infer whether a given inode exists. I don't think that's particularly problematic. Thanks to Jann for bringing this to my attention. * An unrelated note (IOW, these are thoughts that apply to open_by_handle_at() generically and are unrelated to the changes here): Jann pointed out that we should verify whether deleted files could potentially be reopened through open_by_handle_at(). I don't think that's possible though. Another potential thing to check is whether open_by_handle_at() could be abused to open internal stuff like memfds or gpu stuff. I don't think so but I haven't had the time to completely verify this. This dates back to discussions Amir and I had quite some time ago and thanks to him for providing a lot of details around the export code and related patches! Link: https://lore.kernel.org/r/20240524-vfs-open_by_handle_at-v1-1-3d4b7d22736b@kernel.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
* fs: Annotate struct file_handle with __counted_by() and use struct_size()Gustavo A. R. Silva2024-04-051-3/+3
| | | | | | | | | | | | | | | | | | | | Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). While there, use struct_size() helper, instead of the open-coded version. [brauner@kernel.org: contains a fix by Edward for an OOB access] Reported-by: syzbot+4139435cb1b34cf759c2@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis <eadavis@qq.com> Link: https://lore.kernel.org/r/tencent_A7845DD769577306D813742365E976E3A205@qq.com Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/ZgImCXTdGDTeBvSS@neat Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
* do_sys_name_to_handle(): use kzalloc() to fix kernel-infoleakNikita Zhandarovich2024-01-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot identified a kernel information leak vulnerability in do_sys_name_to_handle() and issued the following report [1]. [1] "BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x100 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [inline] _copy_to_user+0xbc/0x100 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [inline] do_sys_name_to_handle fs/fhandle.c:73 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x949/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ... Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x5c9/0x970 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0x121/0x3c0 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] do_sys_name_to_handle fs/fhandle.c:39 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x441/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ... Bytes 18-19 of 20 are uninitialized Memory access of size 20 starts at ffff888128a46380 Data copied to user address 0000000020000240" Per Chuck Lever's suggestion, use kzalloc() instead of kmalloc() to solve the problem. Fixes: 990d6c2d7aee ("vfs: Add name to file handle conversion support") Suggested-by: Chuck Lever III <chuck.lever@oracle.com> Reported-and-tested-by: <syzbot+09b349b3066c2e0b1e96@syzkaller.appspotmail.com> Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> Link: https://lore.kernel.org/r/20240119153906.4367-1-n.zhandarovich@fintech.ru Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
* exportfs: add helpers to check if filesystem can encode/decode file handlesAmir Goldstein2023-10-241-5/+1
| | | | | | | | | | | | | | The logic of whether filesystem can encode/decode file handles is open coded in many places. In preparation to changing the logic, move the open coded logic into inline helpers. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20231023180801.2953446-2-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
* fsnotify: move fsnotify_open() hook into do_dentry_open()Amir Goldstein2023-06-121-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | fsnotify_open() hook is called only from high level system calls context and not called for the very many helpers to open files. This may makes sense for many of the special file open cases, but it is inconsistent with fsnotify_close() hook that is called for every last fput() of on a file object with FMODE_OPENED. As a result, it is possible to observe ACCESS, MODIFY and CLOSE events without ever observing an OPEN event. Fix this inconsistency by replacing all the fsnotify_open() hooks with a single hook inside do_dentry_open(). If there are special cases that would like to opt-out of the possible overhead of fsnotify() call in fsnotify_open(), they would probably also want to avoid the overhead of fsnotify() call in the rest of the fsnotify hooks, so they should be opening that file with the __FMODE_NONOTIFY flag. However, in the majority of those cases, the s_fsnotify_connectors optimization in fsnotify_parent() would be sufficient to avoid the overhead of fsnotify() call anyway. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <20230611122429.1499617-1-amir73il@gmail.com>
* exportfs: check for error return value from exportfs_encode_*()Amir Goldstein2023-05-251-2/+3
| | | | | | | | | | | | | | | | | | | | | The exportfs_encode_*() helpers call the filesystem ->encode_fh() method which returns a signed int. All the in-tree implementations of ->encode_fh() return a positive integer and FILEID_INVALID (255) for error. Fortify the callers for possible future ->encode_fh() implementation that will return a negative error value. name_to_handle_at() would propagate the returned error to the users if filesystem ->encode_fh() method returns an error. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Link: https://lore.kernel.org/linux-fsdevel/ca02955f-1877-4fde-b453-3c1d22794740@kili.mountain/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <20230524154825.881414-1-amir73il@gmail.com>
* exportfs: allow exporting non-decodeable file handles to userspaceAmir Goldstein2023-05-251-8/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some userspace programs use st_ino as a unique object identifier, even though inode numbers may be recycable. This issue has been addressed for NFS export long ago using the exportfs file handle API and the unique file handle identifiers are also exported to userspace via name_to_handle_at(2). fanotify also uses file handles to identify objects in events, but only for filesystems that support NFS export. Relax the requirement for NFS export support and allow more filesystems to export a unique object identifier via name_to_handle_at(2) with the flag AT_HANDLE_FID. A file handle requested with the AT_HANDLE_FID flag, may or may not be usable as an argument to open_by_handle_at(2). To allow filesystems to opt-in to supporting AT_HANDLE_FID, a struct export_operations is required, but even an empty struct is sufficient for encoding FIDs. Acked-by: Jeff Layton <jlayton@kernel.org> Acked-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <20230502124817.3070545-4-amir73il@gmail.com>
* do_sys_name_to_handle(): constify pathAl Viro2022-09-011-1/+1
| | | | | Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch file_open_root() to struct pathAl Viro2021-04-071-1/+1
| | | | | | ... and provide file_open_root_mnt(), using the root of given mount. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: delete repeated words in commentsRandy Dunlap2021-02-241-1/+1
| | | | | | | | | | | | | Delete duplicate words in fs/*.c. The doubled words that are being dropped are: that, be, the, in, and, for Link: https://lkml.kernel.org/r/20201224052810.25315-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/handle.c - fix up kerneldocValdis Klētnieks2019-08-081-1/+1
| | | | | | | | | | | | | When building with W=1, we get some kerneldoc warnings: CC fs/fhandle.o fs/fhandle.c:259: warning: Function parameter or member 'flags' not described in 'sys_open_by_handle_at' fs/fhandle.c:259: warning: Excess function parameter 'flag' description in 'sys_open_by_handle_at' Fix the typo that caused it. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: Copy struct mount.mnt_id to userspace using put_user()David Windsor2018-01-151-2/+1
| | | | | | | | | | | | | | | | | The mnt_id field can be copied with put_user(), so there is no need to use copy_to_user(). In both cases, hardened usercopy is being bypassed since the size is constant, and not open to runtime manipulation. This patch is verbatim from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Signed-off-by: David Windsor <dave@nullcore.net> [kees: adjust commit log] Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* Merge branch 'work.misc' of ↵Linus Torvalds2017-11-171-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted stuff, really no common topic here" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: grab the lock instead of blocking in __fd_install during resizing vfs: stop clearing close on exec when closing a fd include/linux/fs.h: fix comment about struct address_space fs: make fiemap work from compat_ioctl coda: fix 'kernel memory exposure attempt' in fsync pstore: remove unneeded unlikely() vfs: remove unneeded unlikely() stubs for mount_bdev() and kill_block_super() in !CONFIG_BLOCK case make vfs_ustat() static do_handle_open() should be static elf_fdpic: fix unused variable warning fold destroy_super() into __put_super() new helper: destroy_unused_super() fix address space warnings in ipc/ acct.h: get rid of detritus
| * do_handle_open() should be staticAl Viro2017-10-141-2/+2
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fhandle: move compat syscalls from compat.cAl Viro2017-04-171-0/+13
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds2016-12-241-1/+1
| | | | | | | | | | | | | This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/coredump: prevent fsuid=0 dumps into user-controlled directoriesJann Horn2016-03-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit fixes the following security hole affecting systems where all of the following conditions are fulfilled: - The fs.suid_dumpable sysctl is set to 2. - The kernel.core_pattern sysctl's value starts with "/". (Systems where kernel.core_pattern starts with "|/" are not affected.) - Unprivileged user namespace creation is permitted. (This is true on Linux >=3.8, but some distributions disallow it by default using a distro patch.) Under these conditions, if a program executes under secure exec rules, causing it to run with the SUID_DUMP_ROOT flag, then unshares its user namespace, changes its root directory and crashes, the coredump will be written using fsuid=0 and a path derived from kernel.core_pattern - but this path is interpreted relative to the root directory of the process, allowing the attacker to control where a coredump will be written with root privileges. To fix the security issue, always interpret core_pattern for dumps that are written under SUID_DUMP_ROOT relative to the root directory of init. Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: read file_handle only once in handle_to_pathSasha Levin2015-06-021-2/+3
| | | | | | | | | | | | | | | | | | We used to read file_handle twice. Once to get the amount of extra bytes, and once to fetch the entire structure. This may be problematic since we do size verifications only after the first read, so if the number of extra bytes changes in userspace between the first and second calls, we'll have an incoherent view of file_handle. Instead, read the constant size once, and copy that over to the final structure without having to re-read it again. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-3.8' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2012-12-201-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull nfsd update from Bruce Fields: "Included this time: - more nfsd containerization work from Stanislav Kinsbursky: we're not quite there yet, but should be by 3.9. - NFSv4.1 progress: implementation of basic backchannel security negotiation and the mandatory BACKCHANNEL_CTL operation. See http://wiki.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues for remaining TODO's - Fixes for some bugs that could be triggered by unusual compounds. Our xdr code wasn't designed with v4 compounds in mind, and it shows. A more thorough rewrite is still a todo. - If you've ever seen "RPC: multiple fragments per record not supported" logged while using some sort of odd userland NFS client, that should now be fixed. - Further work from Jeff Layton on our mechanism for storing information about NFSv4 clients across reboots. - Further work from Bryan Schumaker on his fault-injection mechanism (which allows us to discard selective NFSv4 state, to excercise rarely-taken recovery code paths in the client.) - The usual mix of miscellaneous bugs and cleanup. Thanks to everyone who tested or contributed this cycle." * 'for-3.8' of git://linux-nfs.org/~bfields/linux: (111 commits) nfsd4: don't leave freed stateid hashed nfsd4: free_stateid can use the current stateid nfsd4: cleanup: replace rq_resused count by rq_next_page pointer nfsd: warn on odd reply state in nfsd_vfs_read nfsd4: fix oops on unusual readlike compound nfsd4: disable zero-copy on non-final read ops svcrpc: fix some printks NFSD: Correct the size calculation in fault_inject_write NFSD: Pass correct buffer size to rpc_ntop nfsd: pass proper net to nfsd_destroy() from NFSd kthreads nfsd: simplify service shutdown nfsd: replace boolean nfsd_up flag by users counter nfsd: simplify NFSv4 state init and shutdown nfsd: introduce helpers for generic resources init and shutdown nfsd: make NFSd service structure allocated per net nfsd: make NFSd service boot time per-net nfsd: per-net NFSd up flag introduced nfsd: move per-net startup code to separated function nfsd: pass net to __write_ports() and down nfsd: pass net to nfsd_set_nrthreads() ...
| * exportfs: add FILEID_INVALID to indicate invalid fid_typeNamjae Jeon2012-11-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | This commit adds FILEID_INVALID = 0xff in fid_type to indicate invalid fid_type It avoids using magic number 255 Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Vivek Trivedi <vtrivedi018@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* | Fix misspellings of "whether" in comments.Adam Buchbinder2012-11-191-2/+2
|/ | | | | | | | "Whether" is misspelled in various comments across the tree; this fixes them. No code changes. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* switch simple cases of fget_light to fdgetAl Viro2012-09-271-10/+7
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: prefer ->dentry->d_sb to ->mnt->mnt_sbAl Viro2012-01-071-2/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: mnt_id/mnt_group_id movedAl Viro2012-01-041-1/+3
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/fhandle.c: add <linux/personality.h> for ia64Jeff Mahoney2011-04-151-0/+1
| | | | | | | | | | force_o_largefile() on ia64 is defined in <asm/fcntl.h> and requires <linux/personality.h>. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: Add open by file handle supportAneesh Kumar K.V2011-03-151-0/+158
| | | | | | | [AV: duplicate of open() guts removed; file_open_root() used instead] Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: Add name to file handle conversion supportAneesh Kumar K.V2011-03-151-0/+107
The syscall also return mount id which can be used to lookup file system specific information such as uuid in /proc/<pid>/mountinfo Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>