* [PATCH] PM: hibernate: Fix crash when freeing invalid crypto compressor
@ 2025-12-24 18:20 Malaya Kumar Rout
2025-12-26 13:20 ` Rafael J. Wysocki
0 siblings, 1 reply; 4+ messages in thread
From: Malaya Kumar Rout @ 2025-12-24 18:20 UTC (permalink / raw)
To: linux-kernel
Cc: mrout, malayarout91, Rafael J. Wysocki, Len Brown, Pavel Machek,
linux-pm
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.
Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
---
kernel/power/swap.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 33a186373bef..8ee2fa995580 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -902,8 +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);
- acomp_request_free(data[thr].cr);
- crypto_free_acomp(data[thr].cc);
+ 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);
}
@@ -1499,8 +1501,10 @@ 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);
- acomp_request_free(data[thr].cr);
- crypto_free_acomp(data[thr].cc);
+ 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);
}
--
2.51.0
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] PM: hibernate: Fix crash when freeing invalid crypto compressor
2025-12-24 18:20 [PATCH] PM: hibernate: Fix crash when freeing invalid crypto compressor Malaya Kumar Rout
@ 2025-12-26 13:20 ` Rafael J. Wysocki
2025-12-30 11:56 ` [PATCH v2] " Malaya Kumar Rout
0 siblings, 1 reply; 4+ messages in thread
From: Rafael J. Wysocki @ 2025-12-26 13:20 UTC (permalink / raw)
To: Malaya Kumar Rout
Cc: linux-kernel, malayarout91, Rafael J. Wysocki, Len Brown,
Pavel Machek, linux-pm
On Wed, Dec 24, 2025 at 7:21 PM Malaya Kumar Rout <mrout@redhat.com> wrote:
>
> 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.
>
> Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
I think that it should be possible to find a specific commit fixed by
this and provide a Fixes: tag pointing to it.
Can you please do so?
> ---
> kernel/power/swap.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/power/swap.c b/kernel/power/swap.c
> index 33a186373bef..8ee2fa995580 100644
> --- a/kernel/power/swap.c
> +++ b/kernel/power/swap.c
> @@ -902,8 +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);
> - acomp_request_free(data[thr].cr);
> - crypto_free_acomp(data[thr].cc);
> + 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);
> }
> @@ -1499,8 +1501,10 @@ 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);
> - acomp_request_free(data[thr].cr);
> - crypto_free_acomp(data[thr].cc);
> + 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);
> }
> --
> 2.51.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v2] PM: hibernate: Fix crash when freeing invalid crypto compressor
2025-12-26 13:20 ` Rafael J. Wysocki
@ 2025-12-30 11:56 ` Malaya Kumar Rout
2026-01-05 18:15 ` Rafael J. Wysocki
0 siblings, 1 reply; 4+ messages in thread
From: Malaya Kumar Rout @ 2025-12-30 11:56 UTC (permalink / raw)
To: rafael
Cc: Malaya Kumar Rout, Len Brown, Pavel Machek, Herbert Xu, linux-pm,
linux-kernel
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: b03d542c3c95 ("PM: hibernate: Use crypto_acomp interface")
Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
---
kernel/power/swap.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 33a186373bef..8ee2fa995580 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -902,8 +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);
- acomp_request_free(data[thr].cr);
- crypto_free_acomp(data[thr].cc);
+ 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);
}
@@ -1499,8 +1501,10 @@ 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);
- acomp_request_free(data[thr].cr);
- crypto_free_acomp(data[thr].cc);
+ 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);
}
--
2.52.0
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2] PM: hibernate: Fix crash when freeing invalid crypto compressor
2025-12-30 11:56 ` [PATCH v2] " Malaya Kumar Rout
@ 2026-01-05 18:15 ` Rafael J. Wysocki
0 siblings, 0 replies; 4+ messages in thread
From: Rafael J. Wysocki @ 2026-01-05 18:15 UTC (permalink / raw)
To: Malaya Kumar Rout
Cc: rafael, Len Brown, Pavel Machek, Herbert Xu, linux-pm, linux-kernel
On Tue, Dec 30, 2025 at 12:56 PM Malaya Kumar Rout <mrout@redhat.com> wrote:
>
> 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: b03d542c3c95 ("PM: hibernate: Use crypto_acomp interface")
> Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
> ---
> kernel/power/swap.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/power/swap.c b/kernel/power/swap.c
> index 33a186373bef..8ee2fa995580 100644
> --- a/kernel/power/swap.c
> +++ b/kernel/power/swap.c
> @@ -902,8 +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);
> - acomp_request_free(data[thr].cr);
> - crypto_free_acomp(data[thr].cc);
> + 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);
> }
> @@ -1499,8 +1501,10 @@ 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);
> - acomp_request_free(data[thr].cr);
> - crypto_free_acomp(data[thr].cc);
> + 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);
> }
> --
Applied as 6.19-rc material, thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
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2025-12-24 18:20 [PATCH] PM: hibernate: Fix crash when freeing invalid crypto compressor Malaya Kumar Rout
2025-12-26 13:20 ` Rafael J. Wysocki
2025-12-30 11:56 ` [PATCH v2] " Malaya Kumar Rout
2026-01-05 18:15 ` Rafael J. Wysocki
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