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Serge Hallyn 9f0e4cd4ef fix namespaced fscaps when !CONFIG_SECURITY
[ Upstream commit ed9b25d197 ]

Namespaced file capabilities were introduced in 8db6c34f1d .
When userspace reads an xattr for a namespaced capability, a
virtualized representation of it is returned if the caller is
in a user namespace owned by the capability's owning rootid.
The function which performs this virtualization was not hooked
up if CONFIG_SECURITY=n.  Therefore in that case the original
xattr was shown instead of the virtualized one.

To test this using libcap-bin (*1),

$ v=$(mktemp)
$ unshare -Ur setcap cap_sys_admin-eip $v
$ unshare -Ur setcap -v cap_sys_admin-eip $v
/tmp/tmp.lSiIFRvt8Y: OK

"setcap -v" verifies the values instead of setting them, and
will check whether the rootid value is set.  Therefore, with
this bug un-fixed, and with CONFIG_SECURITY=n, setcap -v will
fail:

$ v=$(mktemp)
$ unshare -Ur setcap cap_sys_admin=eip $v
$ unshare -Ur setcap -v cap_sys_admin=eip $v
nsowner[got=1000, want=0],/tmp/tmp.HHDiOOl9fY differs in []

Fix this bug by calling cap_inode_getsecurity() in
security_inode_getsecurity() instead of returning
-EOPNOTSUPP, when CONFIG_SECURITY=n.

*1 - note, if libcap is too old for getcap to have the '-n'
option, then use verify-caps instead.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=209689
Cc: Hervé Guillemet <herve@guillemet.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Serge Hallyn <shallyn@cisco.com>
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:26:06 +01:00
arch ARM: sunxi: Add machine match for the Allwinner V3 SoC 2020-12-30 11:26:06 +01:00
block block: factor out requeue handling from dispatch code 2020-12-30 11:25:45 +01:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: af_alg - avoid undefined behavior accessing salg_name 2020-12-30 11:25:48 +01:00
Documentation USB: UAS: introduce a quirk to set no_write_same 2020-12-30 11:25:42 +01:00
drivers clk: sunxi-ng: Make sure divider tables have sentinel 2020-12-30 11:26:06 +01:00
firmware Fix built-in early-load Intel microcode alignment 2020-01-23 08:21:29 +01:00
fs nfs_common: need lock during iterate through the list 2020-12-30 11:26:02 +01:00
include fix namespaced fscaps when !CONFIG_SECURITY 2020-12-30 11:26:06 +01:00
init printk: reduce LOG_BUF_SHIFT range for H8300 2020-11-05 11:08:41 +01:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:18:40 +02:00
kernel genirq/irqdomain: Don't try to free an interrupt that has no mapping 2020-12-30 11:25:58 +01:00
lib random32: make prandom_u32() output unpredictable 2020-11-18 19:18:52 +01:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm mm/swapfile: do not sleep with a spin lock held 2020-12-11 13:25:02 +01:00
net cfg80211: initialize rekey_data 2020-12-30 11:26:06 +01:00
samples samples: bpf: Fix lwt_len_hist reusing previous BPF map 2020-12-30 11:25:57 +01:00
scripts kconfig: fix return value of do_error_if() 2020-12-30 11:26:06 +01:00
security selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handling 2020-12-30 11:25:51 +01:00
sound ASoC: wm_adsp: remove "ctl" from list on error in wm_adsp_create_control() 2020-12-30 11:26:03 +01:00
tools perf record: Fix memory leak when using '--user-regs=?' to list registers 2020-12-30 11:26:05 +01:00
usr initramfs: restore default compression behavior 2020-04-13 10:44:59 +02:00
virt KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace 2020-12-02 08:48:07 +01:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-09-26 18:01:31 +02:00
Makefile Kbuild: do not emit debug info for assembly with LLVM_IAS=1 2020-12-30 11:25:37 +01:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.