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authorThomas Weißschuh2024-05-03 15:44:09 +0200
committerKees Cook2024-05-03 12:35:12 -0700
commit0e148d3cca0dc1a7c6063939f6cb9ba4866c39a7 (patch)
treea2f14853623d0ec84dfca6c5ea7616447c0a708f /kernel
parent7d78a77733552092361239b1d8afaf8412f5dffd (diff)
stackleak: Use a copy of the ctl_table argument
Sysctl handlers are not supposed to modify the ctl_table passed to them. Adapt the logic to work with a temporary variable, similar to how it is done in other parts of the kernel. This is also a prerequisite to enforce the immutability of the argument through the callbacks. Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Tycho Andersen <tycho@tycho.pizza> Link: https://lore.kernel.org/r/20240503-sysctl-const-stackleak-v1-1-603fecb19170@weissschuh.net Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/stackleak.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/stackleak.c b/kernel/stackleak.c
index 34c9d81eea94..59cdfaf5118e 100644
--- a/kernel/stackleak.c
+++ b/kernel/stackleak.c
@@ -27,10 +27,10 @@ static int stack_erasing_sysctl(struct ctl_table *table, int write,
int ret = 0;
int state = !static_branch_unlikely(&stack_erasing_bypass);
int prev_state = state;
+ struct ctl_table table_copy = *table;
- table->data = &state;
- table->maxlen = sizeof(int);
- ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ table_copy.data = &state;
+ ret = proc_dointvec_minmax(&table_copy, write, buffer, lenp, ppos);
state = !!state;
if (ret || !write || state == prev_state)
return ret;