kernel.git/fs/xattr.c, branch linux-6.15.y

fs/xattr.c: fix simple_xattr_list()

2025-06-27T10:13:30Z

[ Upstream commit 800d0b9b6a8b1b354637b4194cc167ad1ce2bdd3 ] commit 8b0ba61df5a1 ("fs/xattr.c: fix simple_xattr_list to always include security.* xattrs") failed to reset err after the call to security_inode_listsecurity(), which returns the length of the returned xattr name. This results in simple_xattr_list() incorrectly returning this length even if a POSIX acl is also set on the inode. Reported-by: Collin Funk Closes: https://lore.kernel.org/selinux/8734ceal7q.fsf@gmail.com/ Reported-by: Paul Eggert Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2369561 Fixes: 8b0ba61df5a1 ("fs/xattr.c: fix simple_xattr_list to always include security.* xattrs") Signed-off-by: Stephen Smalley Link: https://lore.kernel.org/20250605165116.2063-1-stephen.smalley.work@gmail.com Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

fs/xattr.c: fix simple_xattr_list to always include security.* xattrs

2025-04-28T08:53:22Z

The vfs has long had a fallback to obtain the security.* xattrs from the LSM when the filesystem does not implement its own listxattr, but shmem/tmpfs and kernfs later gained their own xattr handlers to support other xattrs. Unfortunately, as a side effect, tmpfs and kernfs-based filesystems like sysfs no longer return the synthetic security.* xattr names via listxattr unless they are explicitly set by userspace or initially set upon inode creation after policy load. coreutils has recently switched from unconditionally invoking getxattr for security.* for ls -Z via libselinux to only doing so if listxattr returns the xattr name, breaking ls -Z of such inodes. Before: $ getfattr -m.* /run/initramfs $ getfattr -m.* /sys/kernel/fscaps $ setfattr -n user.foo /run/initramfs $ getfattr -m.* /run/initramfs user.foo After: $ getfattr -m.* /run/initramfs security.selinux $ getfattr -m.* /sys/kernel/fscaps security.selinux $ setfattr -n user.foo /run/initramfs $ getfattr -m.* /run/initramfs security.selinux user.foo Link: https://lore.kernel.org/selinux/CAFqZXNtF8wDyQajPCdGn=iOawX4y77ph0EcfcqcUUj+T87FKyA@mail.gmail.com/ Link: https://lore.kernel.org/selinux/20250423175728.3185-2-stephen.smalley.work@gmail.com/ Signed-off-by: Stephen Smalley Link: https://lore.kernel.org/20250424152822.2719-1-stephen.smalley.work@gmail.com Fixes: b09e0fa4b4ea66266058ee ("tmpfs: implement generic xattr support") Signed-off-by: Christian Brauner

fs/xattr: Fix handling of AT_FDCWD in setxattrat(2) and getxattrat(2)

2025-04-25T10:11:56Z

Currently, setxattrat(2) and getxattrat(2) are wrongly handling the calls of the from setxattrat(AF_FDCWD, NULL, AT_EMPTY_PATH, ...) and fail with -EBADF error instead of operating on CWD. Fix it. Fixes: 6140be90ec70 ("fs/xattr: add *at family syscalls") Signed-off-by: Jan Kara Link: https://lore.kernel.org/20250424132246.16822-2-jack@suse.cz Signed-off-by: Christian Brauner

xattr: remove redundant check on variable err

2024-11-06T18:00:01Z

Curretly in function generic_listxattr the for_each_xattr_handler loop checks err and will return out of the function if err is non-zero. It's impossible for err to be non-zero at the end of the function where err is checked again for a non-zero value. The final non-zero check is therefore redundant and can be removed. Also move the declaration of err into the loop. Signed-off-by: Colin Ian King Signed-off-by: Al Viro

fs/xattr: add *at family syscalls

2024-11-06T17:59:44Z

Add the four syscalls setxattrat(), getxattrat(), listxattrat() and removexattrat(). Those can be used to operate on extended attributes, especially security related ones, either relative to a pinned directory or on a file descriptor without read access, avoiding a /proc//fd/ detour, requiring a mounted procfs. One use case will be setfiles(8) setting SELinux file contexts ("security.selinux") without race conditions and without a file descriptor opened with read access requiring SELinux read permission. Use the do_{name}at() pattern from fs/open.c. Pass the value of the extended attribute, its length, and for setxattrat(2) the command (XATTR_CREATE or XATTR_REPLACE) via an added struct xattr_args to not exceed six syscall arguments and not merging the AT_* and XATTR_* flags. [AV: fixes by Christian Brauner folded in, the entire thing rebased on top of {filename,file}_...xattr() primitives, treatment of empty pathnames regularized. As the result, AT_EMPTY_PATH+NULL handling is cheap, so f...(2) can use it] Signed-off-by: Christian Göttsche Link: https://lore.kernel.org/r/20240426162042.191916-1-cgoettsche@seltendoof.de Reviewed-by: Arnd Bergmann Reviewed-by: Christian Brauner CC: x86@kernel.org CC: linux-alpha@vger.kernel.org CC: linux-kernel@vger.kernel.org CC: linux-arm-kernel@lists.infradead.org CC: linux-ia64@vger.kernel.org CC: linux-m68k@lists.linux-m68k.org CC: linux-mips@vger.kernel.org CC: linux-parisc@vger.kernel.org CC: linuxppc-dev@lists.ozlabs.org CC: linux-s390@vger.kernel.org CC: linux-sh@vger.kernel.org CC: sparclinux@vger.kernel.org CC: linux-fsdevel@vger.kernel.org CC: audit@vger.kernel.org CC: linux-arch@vger.kernel.org CC: linux-api@vger.kernel.org CC: linux-security-module@vger.kernel.org CC: selinux@vger.kernel.org [brauner: slight tweaks] Signed-off-by: Christian Brauner Signed-off-by: Al Viro

new helpers: file_removexattr(), filename_removexattr()

2024-11-06T17:59:39Z

switch path_removexattrat() and fremovexattr(2) to those Reviewed-by: Christian Brauner Signed-off-by: Al Viro

new helpers: file_listxattr(), filename_listxattr()

2024-11-06T17:59:39Z

switch path_listxattr() and flistxattr(2) to those Reviewed-by: Christian Brauner Signed-off-by: Al Viro

replace do_getxattr() with saner helpers.

2024-11-06T17:59:39Z

similar to do_setxattr() in the previous commit... Reviewed-by: Christian Brauner Signed-off-by: Al Viro

replace do_setxattr() with saner helpers.

2024-11-06T17:59:39Z

io_uring setxattr logics duplicates stuff from fs/xattr.c; provide saner helpers (filename_setxattr() and file_setxattr() resp.) and use them. NB: putname(ERR_PTR()) is a no-op Signed-off-by: Al Viro

new helper: import_xattr_name()

2024-11-06T17:59:39Z

common logics for marshalling xattr names. Reviewed-by: Christian Brauner Signed-off-by: Al Viro