* [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer
@ 2026-05-31 15:15 Mike Rapoport
2026-05-31 16:18 ` David Laight
0 siblings, 1 reply; 7+ messages in thread
From: Mike Rapoport @ 2026-05-31 15:15 UTC (permalink / raw)
To: Paul Moore, Stephen Smalley
Cc: David Laight, Mike Rapoport, Ondrej Mosnacek,
Venkat Rao Bagalkote, selinux, linux-kernel
From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
selinux_genfs_get_sid() allocates memory for a path with __get_free_page().
Such usage does not require a "page" and the size of the buffer should
actually be PATH_MAX which may be less than PAGE_SIZE on some
architectures.
Replace __get_free_page() for allocation of a path buffer with kmalloc()
and make it explicit that the buffer size is PATH_MAX.
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
v2 changes:
* explicitly use kmalloc() with PATH_MAX
security/selinux/hooks.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 0f704380a8c8..19493198ece1 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1336,11 +1336,11 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
struct super_block *sb = dentry->d_sb;
char *buffer, *path;
- buffer = (char *)__get_free_page(GFP_KERNEL);
+ buffer = kmalloc(GFP_KERNEL, PATH_MAX);
if (!buffer)
return -ENOMEM;
- path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
+ path = dentry_path_raw(dentry, buffer, PATH_MAX);
if (IS_ERR(path))
rc = PTR_ERR(path);
else {
@@ -1361,7 +1361,7 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
rc = 0;
}
}
- free_page((unsigned long)buffer);
+ kfree(buffer);
return rc;
}
--
2.53.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer
2026-05-31 15:15 Mike Rapoport
@ 2026-05-31 16:18 ` David Laight
2026-05-31 16:55 ` Mike Rapoport
0 siblings, 1 reply; 7+ messages in thread
From: David Laight @ 2026-05-31 16:18 UTC (permalink / raw)
To: Mike Rapoport
Cc: Paul Moore, Stephen Smalley, Ondrej Mosnacek,
Venkat Rao Bagalkote, selinux, linux-kernel
On Sun, 31 May 2026 18:15:02 +0300
Mike Rapoport <rppt@kernel.org> wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
>
> selinux_genfs_get_sid() allocates memory for a path with __get_free_page().
>
> Such usage does not require a "page" and the size of the buffer should
> actually be PATH_MAX which may be less than PAGE_SIZE on some
> architectures.
>
> Replace __get_free_page() for allocation of a path buffer with kmalloc()
> and make it explicit that the buffer size is PATH_MAX.
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
> v2 changes:
> * explicitly use kmalloc() with PATH_MAX
>
> security/selinux/hooks.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 0f704380a8c8..19493198ece1 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -1336,11 +1336,11 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
> struct super_block *sb = dentry->d_sb;
> char *buffer, *path;
>
> - buffer = (char *)__get_free_page(GFP_KERNEL);
> + buffer = kmalloc(GFP_KERNEL, PATH_MAX);
At least get the args in the right order.
> if (!buffer)
> return -ENOMEM;
>
> - path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
> + path = dentry_path_raw(dentry, buffer, PATH_MAX);
> if (IS_ERR(path))
> rc = PTR_ERR(path);
> else {
> @@ -1361,7 +1361,7 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
> rc = 0;
> }
> }
> - free_page((unsigned long)buffer);
> + kfree(buffer);
> return rc;
> }
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer
2026-05-31 16:18 ` David Laight
@ 2026-05-31 16:55 ` Mike Rapoport
0 siblings, 0 replies; 7+ messages in thread
From: Mike Rapoport @ 2026-05-31 16:55 UTC (permalink / raw)
To: David Laight
Cc: Paul Moore, Stephen Smalley, Ondrej Mosnacek,
Venkat Rao Bagalkote, selinux, linux-kernel
On Sun, May 31, 2026 at 05:18:11PM +0100, David Laight wrote:
> On Sun, 31 May 2026 18:15:02 +0300
> Mike Rapoport <rppt@kernel.org> wrote:
>
> > From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> >
> > selinux_genfs_get_sid() allocates memory for a path with __get_free_page().
> >
> > Such usage does not require a "page" and the size of the buffer should
> > actually be PATH_MAX which may be less than PAGE_SIZE on some
> > architectures.
> >
> > Replace __get_free_page() for allocation of a path buffer with kmalloc()
> > and make it explicit that the buffer size is PATH_MAX.
> >
> > Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> > ---
> > v2 changes:
> > * explicitly use kmalloc() with PATH_MAX
> >
> > security/selinux/hooks.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> > index 0f704380a8c8..19493198ece1 100644
> > --- a/security/selinux/hooks.c
> > +++ b/security/selinux/hooks.c
> > @@ -1336,11 +1336,11 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
> > struct super_block *sb = dentry->d_sb;
> > char *buffer, *path;
> >
> > - buffer = (char *)__get_free_page(GFP_KERNEL);
> > + buffer = kmalloc(GFP_KERNEL, PATH_MAX);
>
> At least get the args in the right order.
oops
--
Sincerely yours,
Mike.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer
@ 2026-06-30 10:15 Mike Rapoport (Microsoft)
2026-06-30 10:23 ` Mike Rapoport
0 siblings, 1 reply; 7+ messages in thread
From: Mike Rapoport (Microsoft) @ 2026-06-30 10:15 UTC (permalink / raw)
To: Paul Moore, Stephen Smalley
Cc: David Laight, Mike Rapoport, Ondrej Mosnacek, linux-kernel,
linux-mm, selinux
selinux_genfs_get_sid() allocates memory for a path with __get_free_page().
Such usage does not require a "page" and the size of the buffer should
actually be PATH_MAX which may be less than PAGE_SIZE on some
architectures.
Replace __get_free_page() for allocation of a path buffer with kmalloc()
and make it explicit that the buffer size is PATH_MAX.
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
This is a (tiny) part of larger work of replacing page allocator calls
with kmalloc:
Also in git:
https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git gfp-to-kmalloc/security
---
v4 changes:
* rebase on v7.2-rc1
v3: https://lore.kernel.org/all/20260531165852.1478916-1-rppt@kernel.org
* get the args in the right order
v2: https://lore.kernel.org/all/20260531151502.1467515-1-rppt@kernel.org
* explicitly use kmalloc() with PATH_MAX
---
security/selinux/hooks.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 1a713d96206f..d1f089917a82 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1336,11 +1336,11 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
struct super_block *sb = dentry->d_sb;
char *buffer, *path;
- buffer = (char *)__get_free_page(GFP_KERNEL);
+ buffer = kmalloc(PATH_MAX, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
- path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
+ path = dentry_path_raw(dentry, buffer, PATH_MAX);
if (IS_ERR(path))
rc = PTR_ERR(path);
else {
@@ -1361,7 +1361,7 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
rc = 0;
}
}
- free_page((unsigned long)buffer);
+ kfree(buffer);
return rc;
}
---
base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
change-id: 20260520-security-6cdd60da7129
Best regards,
--
Sincerely yours,
Mike.
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer
2026-06-30 10:15 [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer Mike Rapoport (Microsoft)
@ 2026-06-30 10:23 ` Mike Rapoport
2026-07-01 1:01 ` Paul Moore
0 siblings, 1 reply; 7+ messages in thread
From: Mike Rapoport @ 2026-06-30 10:23 UTC (permalink / raw)
To: Paul Moore, Stephen Smalley
Cc: David Laight, Ondrej Mosnacek, linux-kernel, linux-mm, selinux
Should have been:
Subject: [PATCH v4] selinux: hooks: use kmalloc() to allocate path buffer
On Tue, Jun 30, 2026 at 01:15:24PM +0300, Mike Rapoport (Microsoft) wrote:
> selinux_genfs_get_sid() allocates memory for a path with __get_free_page().
>
> Such usage does not require a "page" and the size of the buffer should
> actually be PATH_MAX which may be less than PAGE_SIZE on some
> architectures.
>
> Replace __get_free_page() for allocation of a path buffer with kmalloc()
> and make it explicit that the buffer size is PATH_MAX.
>
> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
> This is a (tiny) part of larger work of replacing page allocator calls
> with kmalloc:
>
> Also in git:
> https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git gfp-to-kmalloc/security
> ---
> v4 changes:
> * rebase on v7.2-rc1
>
> v3: https://lore.kernel.org/all/20260531165852.1478916-1-rppt@kernel.org
> * get the args in the right order
>
> v2: https://lore.kernel.org/all/20260531151502.1467515-1-rppt@kernel.org
> * explicitly use kmalloc() with PATH_MAX
> ---
> security/selinux/hooks.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 1a713d96206f..d1f089917a82 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -1336,11 +1336,11 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
> struct super_block *sb = dentry->d_sb;
> char *buffer, *path;
>
> - buffer = (char *)__get_free_page(GFP_KERNEL);
> + buffer = kmalloc(PATH_MAX, GFP_KERNEL);
> if (!buffer)
> return -ENOMEM;
>
> - path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
> + path = dentry_path_raw(dentry, buffer, PATH_MAX);
> if (IS_ERR(path))
> rc = PTR_ERR(path);
> else {
> @@ -1361,7 +1361,7 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
> rc = 0;
> }
> }
> - free_page((unsigned long)buffer);
> + kfree(buffer);
> return rc;
> }
>
>
> ---
> base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
> change-id: 20260520-security-6cdd60da7129
>
> Best regards,
> --
> Sincerely yours,
> Mike.
>
--
Sincerely yours,
Mike.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer
2026-06-30 10:23 ` Mike Rapoport
@ 2026-07-01 1:01 ` Paul Moore
2026-07-01 6:28 ` Mike Rapoport
0 siblings, 1 reply; 7+ messages in thread
From: Paul Moore @ 2026-07-01 1:01 UTC (permalink / raw)
To: Mike Rapoport
Cc: Stephen Smalley, David Laight, Ondrej Mosnacek, linux-kernel,
linux-mm, selinux
On Tue, Jun 30, 2026 at 6:23 AM Mike Rapoport <rppt@kernel.org> wrote:
>
> Should have been:
>
> Subject: [PATCH v4] selinux: hooks: use kmalloc() to allocate path buffer
No worries, I just merged the v3 patchset, it applied cleanly.
> On Tue, Jun 30, 2026 at 01:15:24PM +0300, Mike Rapoport (Microsoft) wrote:
> > selinux_genfs_get_sid() allocates memory for a path with __get_free_page().
> >
> > Such usage does not require a "page" and the size of the buffer should
> > actually be PATH_MAX which may be less than PAGE_SIZE on some
> > architectures.
> >
> > Replace __get_free_page() for allocation of a path buffer with kmalloc()
> > and make it explicit that the buffer size is PATH_MAX.
> >
> > Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
> > Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> > ---
> > This is a (tiny) part of larger work of replacing page allocator calls
> > with kmalloc:
> >
> > Also in git:
> > https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git gfp-to-kmalloc/security
> > ---
> > v4 changes:
> > * rebase on v7.2-rc1
> >
> > v3: https://lore.kernel.org/all/20260531165852.1478916-1-rppt@kernel.org
> > * get the args in the right order
> >
> > v2: https://lore.kernel.org/all/20260531151502.1467515-1-rppt@kernel.org
> > * explicitly use kmalloc() with PATH_MAX
> > ---
> > security/selinux/hooks.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> > index 1a713d96206f..d1f089917a82 100644
> > --- a/security/selinux/hooks.c
> > +++ b/security/selinux/hooks.c
> > @@ -1336,11 +1336,11 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
> > struct super_block *sb = dentry->d_sb;
> > char *buffer, *path;
> >
> > - buffer = (char *)__get_free_page(GFP_KERNEL);
> > + buffer = kmalloc(PATH_MAX, GFP_KERNEL);
> > if (!buffer)
> > return -ENOMEM;
> >
> > - path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
> > + path = dentry_path_raw(dentry, buffer, PATH_MAX);
> > if (IS_ERR(path))
> > rc = PTR_ERR(path);
> > else {
> > @@ -1361,7 +1361,7 @@ static int selinux_genfs_get_sid(struct dentry *dentry,
> > rc = 0;
> > }
> > }
> > - free_page((unsigned long)buffer);
> > + kfree(buffer);
> > return rc;
> > }
> >
> >
> > ---
> > base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
> > change-id: 20260520-security-6cdd60da7129
> >
> > Best regards,
> > --
> > Sincerely yours,
> > Mike.
> >
>
> --
> Sincerely yours,
> Mike.
--
paul-moore.com
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer
2026-07-01 1:01 ` Paul Moore
@ 2026-07-01 6:28 ` Mike Rapoport
0 siblings, 0 replies; 7+ messages in thread
From: Mike Rapoport @ 2026-07-01 6:28 UTC (permalink / raw)
To: Paul Moore
Cc: Stephen Smalley, David Laight, Ondrej Mosnacek, linux-kernel,
linux-mm, selinux
On Tue, Jun 30, 2026 at 09:01:08PM -0400, Paul Moore wrote:
> On Tue, Jun 30, 2026 at 6:23 AM Mike Rapoport <rppt@kernel.org> wrote:
> >
> > Should have been:
> >
> > Subject: [PATCH v4] selinux: hooks: use kmalloc() to allocate path buffer
>
> No worries, I just merged the v3 patchset, it applied cleanly.
Thanks, Paul!
--
Sincerely yours,
Mike.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2026-07-01 6:29 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2026-06-30 10:15 [PATCH v2] selinux: hooks: use kmalloc() to allocate path buffer Mike Rapoport (Microsoft)
2026-06-30 10:23 ` Mike Rapoport
2026-07-01 1:01 ` Paul Moore
2026-07-01 6:28 ` Mike Rapoport
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