i/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

kernel: make groups_sort calling a responsibility group_info allocators

Browse Source 
commit bdcf0a423ea1c40bbb40e7ee483b50fc8aa3d758 upstream.

In testing, we found that nfsd threads may call set_groups in parallel
for the same entry cached in auth.unix.gid, racing in the call of
groups_sort, corrupting the groups for that entry and leading to
permission denials for the client.

This patch:
 - Make groups_sort globally visible.
 - Move the call to groups_sort to the modifiers of group_info
 - Remove the call to groups_sort from set_groups

Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com
Signed-off-by: Thiago Rafael Becker <thiago.becker@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thiago Rafael Becker
2017-12-14 15:33:12 -08:00
committed by Greg Kroah-Hartman
parent 3a381abc5b
commit 79258d9834
8 changed files with 13 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/groups.c
+3 -2
View File
@@ -77,7 +77,7 @@ static int groups_from_user(struct group_info *group_info,
}
/* a simple Shell sort */
static void groups_sort(struct group_info *group_info)
void groups_sort(struct group_info *group_info)
{
int base, max, stride;
int gidsetsize = group_info->ngroups;
@@ -103,6 +103,7 @@ static void groups_sort(struct group_info *group_info)
stride /= 3;
}
}
EXPORT_SYMBOL(groups_sort);
/* a simple bsearch */
int groups_search(const struct group_info *group_info, kgid_t grp)
@@ -134,7 +135,6 @@ int groups_search(const struct group_info *group_info, kgid_t grp)
void set_groups(struct cred *new, struct group_info *group_info)
{
put_group_info(new->group_info);
groups_sort(group_info);
get_group_info(group_info);
new->group_info = group_info;
}
@@ -218,6 +218,7 @@ SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
return retval;
}
groups_sort(group_info);
retval = set_current_groups(group_info);
put_group_info(group_info);
kernel/uid16.c
+1
View File
@@ -190,6 +190,7 @@ SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
return retval;
}
groups_sort(group_info);
retval = set_current_groups(group_info);
put_group_info(group_info);