kernel/linux.git/fs/sysv/super.c, branch v6.6.131

fs: sysv: check sbi->s_firstdatazone in complete_read_super

2022-04-29T21:38:04+00:00

sbi->s_firstinodezone is initialized to 2 and sbi->s_firstdatazone is read from sbd. There's no guarantee that sbi->s_firstdatazone must bigger than sbi->s_firstinodezone. If sbi->s_firstdatazone less than 2, the filesystem can still be mounted unexpetly. At this point, sbi->s_ninodes flip to very large value and this filesystem is broken. We can observe this by executing 'df' command. When we execute, we will get an error message: "sysv_count_free_inodes: unable to read inode table" Link: https://lkml.kernel.org/r/20220330104215.530223-1-liushixin2@huawei.com Signed-off-by: Liu Shixin Reviewed-by: Christoph Hellwig Signed-off-by: Andrew Morton

sysv: use BUILD_BUG_ON instead of runtime check

2021-11-09T18:02:52+00:00

There were runtime checks about sizes of struct v7_super_block and struct sysv_inode. If one of these checks fail the kernel will panic. Since these values are known at compile time let's use BUILD_BUG_ON(), because it's a standard mechanism for validation checking at build time Link: https://lkml.kernel.org/r/20210813123020.22971-1-paskripkin@gmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Pavel Skripkin Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: sysv: Initialize filesystem timestamp ranges

2019-08-30T14:27:18+00:00

Fill in the appropriate limits to avoid inconsistencies in the vfs cached inode times when timestamps are outside the permitted range. Signed-off-by: Deepa Dinamani Acked-by: Jeff Layton Cc: hch@infradead.org

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

sysv: bury the broken "quietly truncate the long filenames" logics

2019-04-09T23:21:06+00:00

It's contrary to the normal semantics, only sysv and adfs try to do that (on any other filesystem you'll get -ENAMETOOLONG instead of quiet truncation) and nobody actually uses that - it got accidentally broken 5 years ago and nobody noticed. Time to bury it... Signed-off-by: Al Viro

Rename superblock flags (MS_xyz -> SB_xyz)

2017-11-27T21:05:09+00:00

This is a pure automated search-and-replace of the internal kernel superblock flags. The s_flags are now called SB_*, with the names and the values for the moment mirroring the MS_* flags that they're equivalent to. Note how the MS_xyz flags are the ones passed to the mount system call, while the SB_xyz flags are what we then use in sb->s_flags. The script to do this was: # places to look in; re security/*: it generally should *not* be # touched (that stuff parses mount(2) arguments directly), but # there are two places where we really deal with superblock flags. FILES="drivers/mtd drivers/staging/lustre fs ipc mm \ include/linux/fs.h include/uapi/linux/bfs_fs.h \ security/apparmor/apparmorfs.c security/apparmor/include/lib.h" # the list of MS_... constants SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \ DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \ POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \ I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \ ACTIVE NOUSER" SED_PROG= for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done # we want files that contain at least one of MS_..., # with fs/namespace.c and fs/pnode.c excluded. L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c') for f in $L; do sed -i $f $SED_PROG; done Requested-by: Al Viro Signed-off-by: Linus Torvalds

VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)

2017-07-17T07:45:34+00:00

Firstly by applying the following with coccinelle's spatch: @@ expression SB; @@ -SB->s_flags & MS_RDONLY +sb_rdonly(SB) to effect the conversion to sb_rdonly(sb), then by applying: @@ expression A, SB; @@ ( -(!sb_rdonly(SB)) && A +!sb_rdonly(SB) && A | -A != (sb_rdonly(SB)) +A != sb_rdonly(SB) | -A == (sb_rdonly(SB)) +A == sb_rdonly(SB) | -!(sb_rdonly(SB)) +!sb_rdonly(SB) | -A && (sb_rdonly(SB)) +A && sb_rdonly(SB) | -A || (sb_rdonly(SB)) +A || sb_rdonly(SB) | -(sb_rdonly(SB)) != A +sb_rdonly(SB) != A | -(sb_rdonly(SB)) == A +sb_rdonly(SB) == A | -(sb_rdonly(SB)) && A +sb_rdonly(SB) && A | -(sb_rdonly(SB)) || A +sb_rdonly(SB) || A ) @@ expression A, B, SB; @@ ( -(sb_rdonly(SB)) ? 1 : 0 +sb_rdonly(SB) | -(sb_rdonly(SB)) ? A : B +sb_rdonly(SB) ? A : B ) to remove left over excess bracketage and finally by applying: @@ expression A, SB; @@ ( -(A & MS_RDONLY) != sb_rdonly(SB) +(bool)(A & MS_RDONLY) != sb_rdonly(SB) | -(A & MS_RDONLY) == sb_rdonly(SB) +(bool)(A & MS_RDONLY) == sb_rdonly(SB) ) to make comparisons against the result of sb_rdonly() (which is a bool) work correctly. Signed-off-by: David Howells

sysv: Add forgotten superblock lock init for v7 fs

2013-09-30T02:02:02+00:00

Superblock lock was replaced with (un)lock_super() removal, but left uninitialized for Seventh Edition UNIX filesystem in the following commit (3.7): c07cb01 sysv: drop lock/unlock super Signed-off-by: Lubomir Rintel Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

fs: Readd the fs module aliases.

2013-03-13T01:55:21+00:00

I had assumed that the only use of module aliases for filesystems prior to "fs: Limit sys_mount to only request filesystem modules." was in request_module. It turns out I was wrong. At least mkinitcpio in Arch linux uses these aliases. So readd the preexising aliases, to keep from breaking userspace. Userspace eventually will have to follow and use the same aliases the kernel does. So at some point we may be delete these aliases without problems. However that day is not today. Signed-off-by: "Eric W. Biederman"

fs: Limit sys_mount to only request filesystem modules.

2013-03-04T03:36:31+00:00

Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn Acked-by: Kees Cook Reported-by: Kees Cook Signed-off-by: "Eric W. Biederman"