| Message ID | 20240429-strncpy-kernel-power-hibernate-c-v1-1-8688f492d3e6@google.com |
|---|---|
| State | Accepted |
| Commit | 7b831bd3cf322fdacd07f321d6d7297914ed79bc |
| Headers | show |
| Series | PM: hibernate: replace deprecated strncpy with strscpy | expand |
On Apr 29, 2024 at 20:50:30 +0000, Justin Stitt wrote: > strncpy() is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. > > This kernel config option is simply assigned with the resume_file > buffer. It should be NUL-terminated but not necessarily NUL-padded as > per its further usage with other string apis: > | static int __init find_resume_device(void) > | { > | if (!strlen(resume_file)) > | return -ENOENT; > | > | pm_pr_dbg("Checking hibernation image partition %s\n", resume_file); > > Use strscpy [2] as it guarantees NUL-termination on the destination > buffer. Specifically, use the new 2-argument version of strscpy() > introduced in Commit e6584c3964f2f ("string: Allow 2-argument > strscpy()"). > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Justin Stitt <justinstitt@google.com> > --- [...] Reviewed-by: Dhruva Gole <d-gole@ti.com>
On Tue, Apr 30, 2024 at 11:36 AM Dhruva Gole <d-gole@ti.com> wrote: > > On Apr 29, 2024 at 20:50:30 +0000, Justin Stitt wrote: > > strncpy() is deprecated for use on NUL-terminated destination strings > > [1] and as such we should prefer more robust and less ambiguous string > > interfaces. > > > > This kernel config option is simply assigned with the resume_file > > buffer. It should be NUL-terminated but not necessarily NUL-padded as > > per its further usage with other string apis: > > | static int __init find_resume_device(void) > > | { > > | if (!strlen(resume_file)) > > | return -ENOENT; > > | > > | pm_pr_dbg("Checking hibernation image partition %s\n", resume_file); > > > > Use strscpy [2] as it guarantees NUL-termination on the destination > > buffer. Specifically, use the new 2-argument version of strscpy() > > introduced in Commit e6584c3964f2f ("string: Allow 2-argument > > strscpy()"). > > > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > > Link: https://github.com/KSPP/linux/issues/90 > > Cc: linux-hardening@vger.kernel.org > > Signed-off-by: Justin Stitt <justinstitt@google.com> > > --- > [...] > > Reviewed-by: Dhruva Gole <d-gole@ti.com> Applied as 6.10 material, thanks!
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 43b1a82e800c..0a213f69a9e4 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -1361,7 +1361,7 @@ static int __init resume_setup(char *str) if (noresume) return 1; - strncpy(resume_file, str, 255); + strscpy(resume_file, str); return 1; }
strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. This kernel config option is simply assigned with the resume_file buffer. It should be NUL-terminated but not necessarily NUL-padded as per its further usage with other string apis: | static int __init find_resume_device(void) | { | if (!strlen(resume_file)) | return -ENOENT; | | pm_pr_dbg("Checking hibernation image partition %s\n", resume_file); Use strscpy [2] as it guarantees NUL-termination on the destination buffer. Specifically, use the new 2-argument version of strscpy() introduced in Commit e6584c3964f2f ("string: Allow 2-argument strscpy()"). Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt <justinstitt@google.com> --- Note: build-tested only. Found with: $ rg "strncpy\(" --- kernel/power/hibernate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: d7ad0581567927c433918bb5f06f3d29f89807d3 change-id: 20240412-strncpy-kernel-power-hibernate-c-77985696443c Best regards, -- Justin Stitt <justinstitt@google.com>