6.12-stable review patch. If anyone has any objections, please let me know.
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From: John Johansen john.johansen@canonical.com
[ Upstream commit a9eb185be84e998aa9a99c7760534ccc06216705 ]
x_table_lookup currently does stacking during label_parse() if the target specifies a stack but its only caller ensures that it will never be used with stacking.
Refactor to slightly simplify the code in x_to_label(), this also fixes a long standing problem where x_to_labels check on stacking is only on the first element to the table option list, instead of the element that is found and used.
Signed-off-by: John Johansen john.johansen@canonical.com Signed-off-by: Sasha Levin sashal@kernel.org --- security/apparmor/domain.c | 52 +++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 23 deletions(-)
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 571158ec6188..cccd61cca509 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -509,6 +509,7 @@ static const char *next_name(int xtype, const char *name) * @name: returns: name tested to find label (NOT NULL) * * Returns: refcounted label, or NULL on failure (MAYBE NULL) + * @name will always be set with the last name tried */ struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, const char **name) @@ -518,6 +519,7 @@ struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, struct aa_label *label = NULL; u32 xtype = xindex & AA_X_TYPE_MASK; int index = xindex & AA_X_INDEX_MASK; + const char *next;
AA_BUG(!name);
@@ -525,25 +527,27 @@ struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, /* TODO: move lookup parsing to unpack time so this is a straight * index into the resultant label */ - for (*name = rules->file->trans.table[index]; !label && *name; - *name = next_name(xtype, *name)) { + for (next = rules->file->trans.table[index]; next; + next = next_name(xtype, next)) { + const char *lookup = (*next == '&') ? next + 1 : next; + *name = next; if (xindex & AA_X_CHILD) { - struct aa_profile *new_profile; - /* release by caller */ - new_profile = aa_find_child(profile, *name); - if (new_profile) - label = &new_profile->label; + /* TODO: switich to parse to get stack of child */ + struct aa_profile *new = aa_find_child(profile, lookup); + + if (new) + /* release by caller */ + return &new->label; continue; } - label = aa_label_parse(&profile->label, *name, GFP_KERNEL, + label = aa_label_parse(&profile->label, lookup, GFP_KERNEL, true, false); - if (IS_ERR(label)) - label = NULL; + if (!IS_ERR_OR_NULL(label)) + /* release by caller */ + return label; }
- /* released by caller */ - - return label; + return NULL; }
/** @@ -568,9 +572,9 @@ static struct aa_label *x_to_label(struct aa_profile *profile, struct aa_ruleset *rules = list_first_entry(&profile->rules, typeof(*rules), list); struct aa_label *new = NULL; + struct aa_label *stack = NULL; struct aa_ns *ns = profile->ns; u32 xtype = xindex & AA_X_TYPE_MASK; - const char *stack = NULL;
switch (xtype) { case AA_X_NONE: @@ -579,13 +583,14 @@ static struct aa_label *x_to_label(struct aa_profile *profile, break; case AA_X_TABLE: /* TODO: fix when perm mapping done at unload */ - stack = rules->file->trans.table[xindex & AA_X_INDEX_MASK]; - if (*stack != '&') { - /* released by caller */ - new = x_table_lookup(profile, xindex, lookupname); - stack = NULL; + /* released by caller + * if null for both stack and direct want to try fallback + */ + new = x_table_lookup(profile, xindex, lookupname); + if (!new || **lookupname != '&') break; - } + stack = new; + new = NULL; fallthrough; /* to X_NAME */ case AA_X_NAME: if (xindex & AA_X_CHILD) @@ -600,6 +605,7 @@ static struct aa_label *x_to_label(struct aa_profile *profile, break; }
+ /* fallback transition check */ if (!new) { if (xindex & AA_X_INHERIT) { /* (p|c|n)ix - don't change profile but do @@ -618,12 +624,12 @@ static struct aa_label *x_to_label(struct aa_profile *profile, /* base the stack on post domain transition */ struct aa_label *base = new;
- new = aa_label_parse(base, stack, GFP_KERNEL, true, false); - if (IS_ERR(new)) - new = NULL; + new = aa_label_merge(base, stack, GFP_KERNEL); + /* null on error */ aa_put_label(base); }
+ aa_put_label(stack); /* released by caller */ return new; }