From: Chen Ridong chenridong@huawei.com
Currently, when the command line contains "nokaslrxxx", it was incorrectly treated as a request to disable KASLR virtual memory. However, the behavior is different from physical address handling.
This issue exists before the commit af73b9a2dd39 ("arm64: kaslr: Use feature override instead of parsing the cmdline again"). This patch fixes the parsing logic for the 'nokaslr' command line argument. Only the exact strings, 'nokaslr', will disable KASLR. Other inputs such as 'xxnokaslr', 'xxnokaslrxx', or 'xxnokaslr=xx' will not disable KASLR.
Fixes: f80fb3a3d508 ("arm64: add support for kernel ASLR") Cc: stable@vger.kernel.org # <= v6.6 Signed-off-by: Chen Ridong chenridong@huawei.com --- arch/arm64/kernel/pi/kaslr_early.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/pi/kaslr_early.c b/arch/arm64/kernel/pi/kaslr_early.c index 17bff6e399e4..731d0a3f1a89 100644 --- a/arch/arm64/kernel/pi/kaslr_early.c +++ b/arch/arm64/kernel/pi/kaslr_early.c @@ -35,9 +35,14 @@ static char *__strstr(const char *s1, const char *s2) static bool cmdline_contains_nokaslr(const u8 *cmdline) { const u8 *str; + size_t len = strlen("nokaslr"); + const char *after = cmdline + len;
str = __strstr(cmdline, "nokaslr"); - return str == cmdline || (str > cmdline && *(str - 1) == ' '); + if ((str == cmdline || (str > cmdline && *(str - 1) == ' ')) && + (*after == ' ' || *after == '\0')) + return true; + return false; }
static bool is_kaslr_disabled_cmdline(void *fdt)
[ Sasha's backport helper bot ]
Hi,
Summary of potential issues: ⚠️ Could not find matching upstream commit
No upstream commit was identified. Using temporary commit for testing.
Results of testing on various branches:
| Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | stable/linux-6.6.y | Success | Success |
On Tue, Jun 03, 2025 at 12:52:33PM +0000, Chen Ridong wrote:
From: Chen Ridong chenridong@huawei.com
Currently, when the command line contains "nokaslrxxx", it was incorrectly treated as a request to disable KASLR virtual memory. However, the behavior is different from physical address handling.
This issue exists before the commit af73b9a2dd39 ("arm64: kaslr: Use feature override instead of parsing the cmdline again"). This patch fixes the parsing logic for the 'nokaslr' command line argument. Only the exact strings, 'nokaslr', will disable KASLR. Other inputs such as 'xxnokaslr', 'xxnokaslrxx', or 'xxnokaslr=xx' will not disable KASLR.
Fixes: f80fb3a3d508 ("arm64: add support for kernel ASLR") Cc: stable@vger.kernel.org # <= v6.6 Signed-off-by: Chen Ridong chenridong@huawei.com
arch/arm64/kernel/pi/kaslr_early.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
<formletter>
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
</formletter>
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