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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-08-12 07:20:16 -1000 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-08-12 07:20:16 -1000 |
commit | f8fbb47c6e86c0b75f8df864db702c3e3f757361 (patch) | |
tree | bce872e99dad31bb3bc2806a7505acb86e4b5445 /kernel | |
parent | 59cd4f435ee972b8fb87d50ea36d76929aabf3a3 (diff) | |
parent | f153c2246783ba210493054d99c66353f56423c9 (diff) | |
download | linux-stable-f8fbb47c6e86c0b75f8df864db702c3e3f757361.tar.gz linux-stable-f8fbb47c6e86c0b75f8df864db702c3e3f757361.tar.bz2 linux-stable-f8fbb47c6e86c0b75f8df864db702c3e3f757361.zip |
Merge branch 'for-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ucounts fix from Eric Biederman:
"This fixes the ucount sysctls on big endian architectures.
The counts were expanded to be longs instead of ints, and the sysctl
code was overlooked, so only the low 32bit were being processed. On
litte endian just processing the low 32bits is fine, but on 64bit big
endian processing just the low 32bits results in the high order bits
instead of the low order bits being processed and nothing works
proper.
This change took a little bit to mature as we have the SYSCTL_ZERO,
and SYSCTL_INT_MAX macros that are only usable for sysctls operating
on ints, but unfortunately are not obviously broken. Which resulted in
the versions of this change working on big endian and not on little
endian, because the int SYSCTL_ZERO when extended 64bit wound up being
0x100000000. So we only allowed values greater than 0x100000000 and
less than 0faff. Which unfortunately broken everything that tried to
set the sysctls. (First reported with the windows subsystem for
linux).
I have tested this on x86_64 64bit after first reproducing the
problems with the earlier version of this change, and then verifying
the problems do not exist when we use appropriate long min and max
values for extra1 and extra2"
* 'for-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ucounts: add missing data type changes
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/ucount.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/kernel/ucount.c b/kernel/ucount.c index 77be3bbe3cc4..bb51849e6375 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -58,14 +58,17 @@ static struct ctl_table_root set_root = { .permissions = set_permissions, }; -#define UCOUNT_ENTRY(name) \ - { \ - .procname = name, \ - .maxlen = sizeof(int), \ - .mode = 0644, \ - .proc_handler = proc_dointvec_minmax, \ - .extra1 = SYSCTL_ZERO, \ - .extra2 = SYSCTL_INT_MAX, \ +static long ue_zero = 0; +static long ue_int_max = INT_MAX; + +#define UCOUNT_ENTRY(name) \ + { \ + .procname = name, \ + .maxlen = sizeof(long), \ + .mode = 0644, \ + .proc_handler = proc_doulongvec_minmax, \ + .extra1 = &ue_zero, \ + .extra2 = &ue_int_max, \ } static struct ctl_table user_table[] = { UCOUNT_ENTRY("max_user_namespaces"), |