linux/fs/proc
Linus Torvalds 94f0b2d4a1 proc: only require mm_struct for writing
Commit 591a22c14d ("proc: Track /proc/$pid/attr/ opener mm_struct") we
started using __mem_open() to track the mm_struct at open-time, so that
we could then check it for writes.

But that also ended up making the permission checks at open time much
stricter - and not just for writes, but for reads too.  And that in turn
caused a regression for at least Fedora 29, where NIC interfaces fail to
start when using NetworkManager.

Since only the write side wanted the mm_struct test, ignore any failures
by __mem_open() at open time, leaving reads unaffected.  The write()
time verification of the mm_struct pointer will then catch the failure
case because a NULL pointer will not match a valid 'current->mm'.

Link: https://lore.kernel.org/netdev/YMjTlp2FSJYvoyFa@unreal/
Fixes: 591a22c14d ("proc: Track /proc/$pid/attr/ opener mm_struct")
Reported-and-tested-by: Leon Romanovsky <leon@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-15 10:47:51 -07:00
..
array.c seccomp: Fix CONFIG tests for Seccomp_filters 2021-03-30 22:33:50 -07:00
base.c proc: only require mm_struct for writing 2021-06-15 10:47:51 -07:00
bootconfig.c proc/bootconfig: Fix to use correct quotes for value 2020-06-16 21:21:03 -04:00
cmdline.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
consoles.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 191 2019-05-30 11:29:21 -07:00
cpuinfo.c proc/cpuinfo: switch to ->read_iter 2020-11-06 10:05:18 -08:00
devices.c block: move block-related definitions out of fs.h 2020-06-24 09:16:02 -06:00
fd.c fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
fd.h fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
generic.c proc: save LOC in __xlate_proc_name() 2021-05-06 19:24:11 -07:00
inode.c proc: delete redundant subset=pid check 2021-05-06 19:24:11 -07:00
internal.h fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
interrupts.c proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
kcore.c arm: remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL 2020-12-15 12:13:42 -08:00
kmsg.c proc: faster open/read/close with "permanent" files 2020-04-07 10:43:42 -07:00
loadavg.c sched: loadavg: consolidate LOAD_INT, LOAD_FRAC, CALC_LOAD 2018-10-26 16:26:32 -07:00
Makefile proc: bootconfig: Add /proc/bootconfig to show boot config list 2020-01-13 13:19:39 -05:00
meminfo.c mm: memcontrol: convert NR_FILE_PMDMAPPED account to pages 2021-02-24 13:38:29 -08:00
namespaces.c Merge branch 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-01-29 11:20:24 -08:00
nommu.c mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
page.c mm: Add PG_arch_2 page flag 2020-09-04 12:46:06 +01:00
proc_net.c fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
proc_sysctl.c proc/sysctl: fix function name error in comments 2021-05-06 19:24:11 -07:00
proc_tty.c tty: replace ->proc_fops with ->proc_show 2018-05-16 07:24:30 +02:00
root.c fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
self.c Revert "proc: don't allow async path resolution of /proc/self components" 2021-02-23 20:32:11 -07:00
softirqs.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
stat.c time-namespace-v5.11 2020-12-14 16:35:39 -08:00
task_mmu.c userfaultfd: add minor fault registration mode 2021-05-05 11:27:22 -07:00
task_nommu.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
thread_self.c Revert "proc: don't allow async path resolution of /proc/thread-self components" 2021-02-23 20:32:11 -07:00
uptime.c fs/proc: Respect boottime inside time namespace for /proc/uptime 2020-01-14 12:20:56 +01:00
util.c fs/proc/util.c: include fs/proc/internal.h for name_to_int() 2019-01-04 13:13:45 -08:00
version.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
vmcore.c vmalloc: remove redundant NULL check 2021-02-24 13:38:30 -08:00