From: Breno Leitao Date: Fri, 20 Jun 2025 13:51:23 +0000 (-0700) Subject: Revert "x86/bugs: Make spectre user default depend on MITIGATION_SPECTRE_V2" on v6... X-Git-Tag: v5.15.186~68 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a41f447cb27a1985c17cadc57883966a6b53dd6a;p=thirdparty%2Fkernel%2Fstable.git Revert "x86/bugs: Make spectre user default depend on MITIGATION_SPECTRE_V2" on v6.6 and older This reverts commit 4fc2d289b3cc4cf23ccabe59cf936d1dc49aeda8 which is commit 98fdaeb296f51ef08e727a7cc72e5b5c864c4f4d upstream. commit 7adb96687ce8 ("x86/bugs: Make spectre user default depend on MITIGATION_SPECTRE_V2") depends on commit 72c70f480a70 ("x86/bugs: Add a separate config for Spectre V2"), which introduced MITIGATION_SPECTRE_V2. commit 72c70f480a70 ("x86/bugs: Add a separate config for Spectre V2") never landed in stable tree, thus, stable tree doesn't have MITIGATION_SPECTRE_V2, that said, commit 7adb96687ce8 ("x86/bugs: Make spectre user default depend on MITIGATION_SPECTRE_V2") has no value if the dependecy was not applied. Revert commit 7adb96687ce8 ("x86/bugs: Make spectre user default depend on MITIGATION_SPECTRE_V2") in stable kernel which landed in in 5.4.294, 5.10.238, 5.15.185, 6.1.141 and 6.6.93 stable versions. Cc: David.Kaplan@amd.com Cc: peterz@infradead.org Cc: pawan.kumar.gupta@linux.intel.com Cc: mingo@kernel.org Cc: brad.spengler@opensrcsec.com Cc: stable@vger.kernel.org # 6.6 6.1 5.15 5.10 5.4 Reported-by: Brad Spengler Reported-by: Salvatore Bonaccorso Signed-off-by: Breno Leitao Signed-off-by: Greg Kroah-Hartman --- diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index e0670357d23f8..4bc5d8c97d097 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5445,8 +5445,6 @@ Selecting 'on' will also enable the mitigation against user space to user space task attacks. - Selecting specific mitigation does not force enable - user mitigations. Selecting 'off' will disable both the kernel and the user space protections. diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 30b9292ac58fd..63af3d73d19e5 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1382,13 +1382,9 @@ static __ro_after_init enum spectre_v2_mitigation_cmd spectre_v2_cmd; static enum spectre_v2_user_cmd __init spectre_v2_parse_user_cmdline(void) { - enum spectre_v2_user_cmd mode; char arg[20]; int ret, i; - mode = IS_ENABLED(CONFIG_MITIGATION_SPECTRE_V2) ? - SPECTRE_V2_USER_CMD_AUTO : SPECTRE_V2_USER_CMD_NONE; - switch (spectre_v2_cmd) { case SPECTRE_V2_CMD_NONE: return SPECTRE_V2_USER_CMD_NONE; @@ -1401,7 +1397,7 @@ spectre_v2_parse_user_cmdline(void) ret = cmdline_find_option(boot_command_line, "spectre_v2_user", arg, sizeof(arg)); if (ret < 0) - return mode; + return SPECTRE_V2_USER_CMD_AUTO; for (i = 0; i < ARRAY_SIZE(v2_user_options); i++) { if (match_option(arg, ret, v2_user_options[i].option)) { @@ -1411,8 +1407,8 @@ spectre_v2_parse_user_cmdline(void) } } - pr_err("Unknown user space protection option (%s). Switching to default\n", arg); - return mode; + pr_err("Unknown user space protection option (%s). Switching to AUTO select\n", arg); + return SPECTRE_V2_USER_CMD_AUTO; } static inline bool spectre_v2_in_eibrs_mode(enum spectre_v2_mitigation mode)