user/sven/linux.git/include/linux, branch v5.4.90

proc: fix lookup in /proc/net subdirectories after setns(2)

2021-01-12T19:16:10Z

[ Upstream commit c6c75deda81344c3a95d1d1f606d5cee109e5d54 ] Commit 1fde6f21d90f ("proc: fix /proc/net/* after setns(2)") only forced revalidation of regular files under /proc/net/ However, /proc/net/ is unusual in the sense of /proc/net/foo handlers take netns pointer from parent directory which is old netns. Steps to reproduce: (void)open("/proc/net/sctp/snmp", O_RDONLY); unshare(CLONE_NEWNET); int fd = open("/proc/net/sctp/snmp", O_RDONLY); read(fd, &c, 1); Read will read wrong data from original netns. Patch forces lookup on every directory under /proc/net . Link: https://lkml.kernel.org/r/20201205160916.GA109739@localhost.localdomain Fixes: 1da4d377f943 ("proc: revalidate misc dentries") Signed-off-by: Alexey Dobriyan Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

exec: Transform exec_update_mutex into a rw_semaphore

2021-01-09T12:44:55Z

[ Upstream commit f7cfd871ae0c5008d94b6f66834e7845caa93c15 ] Recently syzbot reported[0] that there is a deadlock amongst the users of exec_update_mutex. The problematic lock ordering found by lockdep was: perf_event_open (exec_update_mutex -> ovl_i_mutex) chown (ovl_i_mutex -> sb_writes) sendfile (sb_writes -> p->lock) by reading from a proc file and writing to overlayfs proc_pid_syscall (p->lock -> exec_update_mutex) While looking at possible solutions it occured to me that all of the users and possible users involved only wanted to state of the given process to remain the same. They are all readers. The only writer is exec. There is no reason for readers to block on each other. So fix this deadlock by transforming exec_update_mutex into a rw_semaphore named exec_update_lock that only exec takes for writing. Cc: Jann Horn Cc: Vasiliy Kulikov Cc: Al Viro Cc: Bernd Edlinger Cc: Oleg Nesterov Cc: Christopher Yeoh Cc: Cyrill Gorcunov Cc: Sargun Dhillon Cc: Christian Brauner Cc: Arnd Bergmann Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Fixes: eea9673250db ("exec: Add exec_update_mutex to replace cred_guard_mutex") [0] https://lkml.kernel.org/r/00000000000063640c05ade8e3de@google.com Reported-by: syzbot+db9cdf3dd1f64252c6ef@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/87ft4mbqen.fsf@x220.int.ebiederm.org Signed-off-by: Eric W. Biederman Signed-off-by: Sasha Levin

rwsem: Implement down_read_interruptible

2021-01-09T12:44:55Z

[ Upstream commit 31784cff7ee073b34d6eddabb95e3be2880a425c ] In preparation for converting exec_update_mutex to a rwsem so that multiple readers can execute in parallel and not deadlock, add down_read_interruptible. This is needed for perf_event_open to be converted (with no semantic changes) from working on a mutex to wroking on a rwsem. Signed-off-by: Eric W. Biederman Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/87k0tybqfy.fsf@x220.int.ebiederm.org Signed-off-by: Sasha Levin

rwsem: Implement down_read_killable_nested

2021-01-09T12:44:55Z

[ Upstream commit 0f9368b5bf6db0c04afc5454b1be79022a681615 ] In preparation for converting exec_update_mutex to a rwsem so that multiple readers can execute in parallel and not deadlock, add down_read_killable_nested. This is needed so that kcmp_lock can be converted from working on a mutexes to working on rw_semaphores. Signed-off-by: Eric W. Biederman Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/87o8jabqh3.fsf@x220.int.ebiederm.org Signed-off-by: Sasha Levin

kdev_t: always inline major/minor helper functions

2021-01-09T12:44:54Z

commit aa8c7db494d0a83ecae583aa193f1134ef25d506 upstream. Silly GCC doesn't always inline these trivial functions. Fixes the following warning: arch/x86/kernel/sys_ia32.o: warning: objtool: cp_stat64()+0xd8: call to new_encode_dev() with UACCESS enabled Link: https://lkml.kernel.org/r/984353b44a4484d86ba9f73884b7306232e25e30.1608737428.git.jpoimboe@redhat.com Signed-off-by: Josh Poimboeuf Reported-by: Randy Dunlap Acked-by: Randy Dunlap [build-tested] Cc: Peter Zijlstra Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

of: fix linker-section match-table corruption

2021-01-06T13:48:37Z

commit 5812b32e01c6d86ba7a84110702b46d8a8531fe9 upstream. Specify type alignment when declaring linker-section match-table entries to prevent gcc from increasing alignment and corrupting the various tables with padding (e.g. timers, irqchips, clocks, reserved memory). This is specifically needed on x86 where gcc (typically) aligns larger objects like struct of_device_id with static extent on 32-byte boundaries which at best prevents matching on anything but the first entry. Specifying alignment when declaring variables suppresses this optimisation. Here's a 64-bit example where all entries are corrupt as 16 bytes of padding has been inserted before the first entry: ffffffff8266b4b0 D __clk_of_table ffffffff8266b4c0 d __of_table_fixed_factor_clk ffffffff8266b5a0 d __of_table_fixed_clk ffffffff8266b680 d __clk_of_table_sentinel And here's a 32-bit example where the 8-byte-aligned table happens to be placed on a 32-byte boundary so that all but the first entry are corrupt due to the 28 bytes of padding inserted between entries: 812b3ec0 D __irqchip_of_table 812b3ec0 d __of_table_irqchip1 812b3fa0 d __of_table_irqchip2 812b4080 d __of_table_irqchip3 812b4160 d irqchip_of_match_end Verified on x86 using gcc-9.3 and gcc-4.9 (which uses 64-byte alignment), and on arm using gcc-7.2. Note that there are no in-tree users of these tables on x86 currently (even if they are included in the image). Fixes: 54196ccbe0ba ("of: consolidate linker section OF match table declarations") Fixes: f6e916b82022 ("irqchip: add basic infrastructure") Cc: stable # 3.9 Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20201123102319.8090-2-johan@kernel.org [ johan: adjust context to 5.4 ] Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman

fscrypt: add fscrypt_is_nokey_name()

2021-01-06T13:48:35Z

commit 159e1de201b6fca10bfec50405a3b53a561096a8 upstream. It's possible to create a duplicate filename in an encrypted directory by creating a file concurrently with adding the encryption key. Specifically, sys_open(O_CREAT) (or sys_mkdir(), sys_mknod(), or sys_symlink()) can lookup the target filename while the directory's encryption key hasn't been added yet, resulting in a negative no-key dentry. The VFS then calls ->create() (or ->mkdir(), ->mknod(), or ->symlink()) because the dentry is negative. Normally, ->create() would return -ENOKEY due to the directory's key being unavailable. However, if the key was added between the dentry lookup and ->create(), then the filesystem will go ahead and try to create the file. If the target filename happens to already exist as a normal name (not a no-key name), a duplicate filename may be added to the directory. In order to fix this, we need to fix the filesystems to prevent ->create(), ->mkdir(), ->mknod(), and ->symlink() on no-key names. (->rename() and ->link() need it too, but those are already handled correctly by fscrypt_prepare_rename() and fscrypt_prepare_link().) In preparation for this, add a helper function fscrypt_is_nokey_name() that filesystems can use to do this check. Use this helper function for the existing checks that fs/crypto/ does for rename and link. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201118075609.120337-2-ebiggers@kernel.org Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman

fix namespaced fscaps when !CONFIG_SECURITY

2020-12-30T10:51:30Z

[ Upstream commit ed9b25d1970a4787ac6a39c2091e63b127ecbfc1 ] Namespaced file capabilities were introduced in 8db6c34f1dbc . 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 Acked-by: Casey Schaufler Signed-off-by: Serge Hallyn Signed-off-by: Andrew G. Morgan Signed-off-by: James Morris Signed-off-by: Sasha Levin

seq_buf: Avoid type mismatch for seq_buf_init

2020-12-30T10:51:21Z

[ Upstream commit d9a9280a0d0ae51dc1d4142138b99242b7ec8ac6 ] Building with W=2 prints a number of warnings for one function that has a pointer type mismatch: linux/seq_buf.h: In function 'seq_buf_init': linux/seq_buf.h:35:12: warning: pointer targets in assignment from 'unsigned char *' to 'char *' differ in signedness [-Wpointer-sign] Change the type in the function prototype according to the type in the structure. Link: https://lkml.kernel.org/r/20201026161108.3707783-1-arnd@kernel.org Fixes: 9a7777935c34 ("tracing: Convert seq_buf fields to be like seq_file fields") Reviewed-by: Cezary Rojewski Signed-off-by: Arnd Bergmann Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

SUNRPC: xprt_load_transport() needs to support the netid "rdma6"

2020-12-30T10:51:16Z

[ Upstream commit d5aa6b22e2258f05317313ecc02efbb988ed6d38 ] According to RFC5666, the correct netid for an IPv6 addressed RDMA transport is "rdma6", which we've supported as a mount option since Linux-4.7. The problem is when we try to load the module "xprtrdma6", that will fail, since there is no modulealias of that name. Fixes: 181342c5ebe8 ("xprtrdma: Add rdma6 option to support NFS/RDMA IPv6") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin