Commit 7966cf0e authored Dec 30, 2025 by Malaya Kumar Rout Committed by Rafael J. Wysocki Jan 05, 2026

PM: hibernate: Fix crash when freeing invalid crypto compressor



When crypto_alloc_acomp() fails, it returns an ERR_PTR value, not NULL.

The cleanup code in save_compressed_image() and load_compressed_image()
unconditionally calls crypto_free_acomp() without checking for ERR_PTR,
which causes crypto_acomp_tfm() to dereference an invalid pointer and
crash the kernel.

This can be triggered when the compression algorithm is unavailable
(e.g., CONFIG_CRYPTO_LZO not enabled).

Fix by adding IS_ERR_OR_NULL() checks before calling crypto_free_acomp()
and acomp_request_free(), similar to the existing kthread_stop() check.

Fixes: b03d542c ("PM: hibernate: Use crypto_acomp interface")
Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
Cc: 6.15+ <stable@vger.kernel.org> # 6.15+
[ rjw: Added 2 empty code lines ]
Link: https://patch.msgid.link/20251230115613.64080-1-mrout@redhat.com


Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 9ace4753

kernel/power/swap.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -902,7 +902,10 @@ static int save_compressed_image(struct swap_map_handle *handle,
		for (thr = 0; thr < nr_threads; thr++) {
		if (data[thr].thr)
		kthread_stop(data[thr].thr);
		if (data[thr].cr)
		acomp_request_free(data[thr].cr);

		if (!IS_ERR_OR_NULL(data[thr].cc))
		crypto_free_acomp(data[thr].cc);
		}
		vfree(data);
		@@ -1499,7 +1502,10 @@ static int load_compressed_image(struct swap_map_handle *handle,
		for (thr = 0; thr < nr_threads; thr++) {
		if (data[thr].thr)
		kthread_stop(data[thr].thr);
		if (data[thr].cr)
		acomp_request_free(data[thr].cr);

		if (!IS_ERR_OR_NULL(data[thr].cc))
		crypto_free_acomp(data[thr].cc);
		}
		vfree(data);