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authorTom Rix <trix@redhat.com>2022-03-20 02:51:43 +0100
committerPetr Mladek <pmladek@suse.com>2022-03-23 13:51:11 +0100
commit5e6ded2e7a5d9c71186acc8f51989ef6e6addda4 (patch)
treeb676e714e34b2b6d19084532e2808a450f95759a /samples
parentlivepatch: Skip livepatch tests if ftrace cannot be configured (diff)
downloadlinux-5e6ded2e7a5d9c71186acc8f51989ef6e6addda4.tar.xz
linux-5e6ded2e7a5d9c71186acc8f51989ef6e6addda4.zip
livepatch: Reorder to use before freeing a pointer
Clang static analysis reports this issue livepatch-shadow-fix1.c:113:2: warning: Use of memory after it is freed pr_info("%s: dummy @ %p, prevented leak @ %p\n", ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The pointer is freed in the previous statement. Reorder the pr_info to report before the free. Similar issue in livepatch-shadow-fix2.c Note that it is a false positive. pr_info() just prints the address. The freed memory is not accessed. Well, the static analyzer could not know this easily. Signed-off-by: Tom Rix <trix@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: David Vernet <void@manifault.com> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> [pmladek@suse.com: Note about that it was false positive.] Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220320015143.2208591-1-trix@redhat.com
Diffstat (limited to 'samples')
-rw-r--r--samples/livepatch/livepatch-shadow-fix1.c2
-rw-r--r--samples/livepatch/livepatch-shadow-fix2.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/samples/livepatch/livepatch-shadow-fix1.c b/samples/livepatch/livepatch-shadow-fix1.c
index 918ce17b43fd..6701641bf12d 100644
--- a/samples/livepatch/livepatch-shadow-fix1.c
+++ b/samples/livepatch/livepatch-shadow-fix1.c
@@ -109,9 +109,9 @@ static void livepatch_fix1_dummy_leak_dtor(void *obj, void *shadow_data)
void *d = obj;
int **shadow_leak = shadow_data;
- kfree(*shadow_leak);
pr_info("%s: dummy @ %p, prevented leak @ %p\n",
__func__, d, *shadow_leak);
+ kfree(*shadow_leak);
}
static void livepatch_fix1_dummy_free(struct dummy *d)
diff --git a/samples/livepatch/livepatch-shadow-fix2.c b/samples/livepatch/livepatch-shadow-fix2.c
index 29fe5cd42047..361046a4f10c 100644
--- a/samples/livepatch/livepatch-shadow-fix2.c
+++ b/samples/livepatch/livepatch-shadow-fix2.c
@@ -61,9 +61,9 @@ static void livepatch_fix2_dummy_leak_dtor(void *obj, void *shadow_data)
void *d = obj;
int **shadow_leak = shadow_data;
- kfree(*shadow_leak);
pr_info("%s: dummy @ %p, prevented leak @ %p\n",
__func__, d, *shadow_leak);
+ kfree(*shadow_leak);
}
static void livepatch_fix2_dummy_free(struct dummy *d)