From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3FDF31B6520; Wed, 25 Sep 2024 11:42:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727264544; cv=none; b=hNXh6/lWNpibwZMik9WjOlAyd27UdJERlctUM0Cxs+AY5Sq5TEsm5uQRs/mRPRoKLrASLImDjS3OKIvm4PD8l9zO+lI4q/3uQqJPqj4bPnurIAV1660G0lZfP3sIq4uRCwszDTVbcZed2zCGBlMUEzg5ks59aV158/kdHu/jalE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727264544; c=relaxed/simple; bh=fS3Q/48pPvCa6bLqolJB6//mXjLbouiRJW9n8sT+kmo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aOex4+XkU4qgFomjjkBiB/XL1lR2jXx1uzM3aT10/h2yaL4YGObse3zCOYMHcMguj0coCxiyYe8ATkBPuij26rvUa8/KL3bNhR2ZJi5d9wgmWiGYne9KVxxeCYgcfgjUSZ/GqUbqqs5ZP/WfaJ7TGHV+c1+AcrPVsidkzs2+iFc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VV6tAi9M; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VV6tAi9M" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61CA3C4CEC3; Wed, 25 Sep 2024 11:42:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727264543; bh=fS3Q/48pPvCa6bLqolJB6//mXjLbouiRJW9n8sT+kmo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VV6tAi9MAWVQZBHcjBHWmjoZL6RhN8C41TLE1b3nPS8+TG9GbzFbDQMYpF2IFA4Sl 6+2rfUwoJMeAvaOY5Fv+RerFY+c+BVzah4M4o0WVK72rdHLj3h4aL8COUuEbTzV8GN NpkZMAlF85v8ELwJNoh2qAF+3map16rq4ww7TOVGT32VgbpeviCtD4SeP4haYChj6+ eGSZ4mYK0BeC3WMVINeosOgMKZ8XlXZ7Pe/d/88c7vcOv/heSDPLk6hZt7/zMT2iRP C2VQ6lneZiDx0DYtOVY602zF2w3+Zotqa/fM3PY61MOW+E1UK/DORKRv3ycynB3TCK fK2gR8qQSFiQQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Roman Kisel , Allen Pais , Kees Cook , Sasha Levin , viro@zeniv.linux.org.uk, brauner@kernel.org, nagvijay@microsoft.com, linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 6.11 118/244] coredump: Standartize and fix logging Date: Wed, 25 Sep 2024 07:25:39 -0400 Message-ID: <20240925113641.1297102-118-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240925113641.1297102-1-sashal@kernel.org> References: <20240925113641.1297102-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.11 Content-Transfer-Encoding: 8bit From: Roman Kisel [ Upstream commit c114e9948c2b6a0b400266e59cc656b59e795bca ] The coredump code does not log the process ID and the comm consistently, logs unescaped comm when it does log it, and does not always use the ratelimited logging. That makes it harder to analyze logs and puts the system at the risk of spamming the system log incase something crashes many times over and over again. Fix that by logging TGID and comm (escaped) consistently and using the ratelimited logging always. Signed-off-by: Roman Kisel Tested-by: Allen Pais Link: https://lore.kernel.org/r/20240718182743.1959160-2-romank@linux.microsoft.com Signed-off-by: Kees Cook Signed-off-by: Sasha Levin --- fs/coredump.c | 43 +++++++++++++++------------------------- include/linux/coredump.h | 22 ++++++++++++++++++++ 2 files changed, 38 insertions(+), 27 deletions(-) diff --git a/fs/coredump.c b/fs/coredump.c index 7f12ff6ad1d3e..87ff71a59fbe7 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -586,8 +586,7 @@ void do_coredump(const kernel_siginfo_t *siginfo) struct subprocess_info *sub_info; if (ispipe < 0) { - printk(KERN_WARNING "format_corename failed\n"); - printk(KERN_WARNING "Aborting core\n"); + coredump_report_failure("format_corename failed, aborting core"); goto fail_unlock; } @@ -607,27 +606,21 @@ void do_coredump(const kernel_siginfo_t *siginfo) * right pid if a thread in a multi-threaded * core_pattern process dies. */ - printk(KERN_WARNING - "Process %d(%s) has RLIMIT_CORE set to 1\n", - task_tgid_vnr(current), current->comm); - printk(KERN_WARNING "Aborting core\n"); + coredump_report_failure("RLIMIT_CORE is set to 1, aborting core"); goto fail_unlock; } cprm.limit = RLIM_INFINITY; dump_count = atomic_inc_return(&core_dump_count); if (core_pipe_limit && (core_pipe_limit < dump_count)) { - printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n", - task_tgid_vnr(current), current->comm); - printk(KERN_WARNING "Skipping core dump\n"); + coredump_report_failure("over core_pipe_limit, skipping core dump"); goto fail_dropcount; } helper_argv = kmalloc_array(argc + 1, sizeof(*helper_argv), GFP_KERNEL); if (!helper_argv) { - printk(KERN_WARNING "%s failed to allocate memory\n", - __func__); + coredump_report_failure("%s failed to allocate memory", __func__); goto fail_dropcount; } for (argi = 0; argi < argc; argi++) @@ -644,8 +637,7 @@ void do_coredump(const kernel_siginfo_t *siginfo) kfree(helper_argv); if (retval) { - printk(KERN_INFO "Core dump to |%s pipe failed\n", - cn.corename); + coredump_report_failure("|%s pipe failed", cn.corename); goto close_fail; } } else { @@ -658,10 +650,8 @@ void do_coredump(const kernel_siginfo_t *siginfo) goto fail_unlock; if (need_suid_safe && cn.corename[0] != '/') { - printk(KERN_WARNING "Pid %d(%s) can only dump core "\ - "to fully qualified path!\n", - task_tgid_vnr(current), current->comm); - printk(KERN_WARNING "Skipping core dump\n"); + coredump_report_failure( + "this process can only dump core to a fully qualified path, skipping core dump"); goto fail_unlock; } @@ -730,13 +720,13 @@ void do_coredump(const kernel_siginfo_t *siginfo) idmap = file_mnt_idmap(cprm.file); if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode), current_fsuid())) { - pr_info_ratelimited("Core dump to %s aborted: cannot preserve file owner\n", - cn.corename); + coredump_report_failure("Core dump to %s aborted: " + "cannot preserve file owner", cn.corename); goto close_fail; } if ((inode->i_mode & 0677) != 0600) { - pr_info_ratelimited("Core dump to %s aborted: cannot preserve file permissions\n", - cn.corename); + coredump_report_failure("Core dump to %s aborted: " + "cannot preserve file permissions", cn.corename); goto close_fail; } if (!(cprm.file->f_mode & FMODE_CAN_WRITE)) @@ -757,7 +747,7 @@ void do_coredump(const kernel_siginfo_t *siginfo) * have this set to NULL. */ if (!cprm.file) { - pr_info("Core dump to |%s disabled\n", cn.corename); + coredump_report_failure("Core dump to |%s disabled", cn.corename); goto close_fail; } if (!dump_vma_snapshot(&cprm)) @@ -983,11 +973,10 @@ void validate_coredump_safety(void) { if (suid_dumpable == SUID_DUMP_ROOT && core_pattern[0] != '/' && core_pattern[0] != '|') { - pr_warn( -"Unsafe core_pattern used with fs.suid_dumpable=2.\n" -"Pipe handler or fully qualified core dump path required.\n" -"Set kernel.core_pattern before fs.suid_dumpable.\n" - ); + + coredump_report_failure("Unsafe core_pattern used with fs.suid_dumpable=2: " + "pipe handler or fully qualified core dump path required. " + "Set kernel.core_pattern before fs.suid_dumpable."); } } diff --git a/include/linux/coredump.h b/include/linux/coredump.h index 0904ba010341a..45e598fe34766 100644 --- a/include/linux/coredump.h +++ b/include/linux/coredump.h @@ -43,8 +43,30 @@ extern int dump_align(struct coredump_params *cprm, int align); int dump_user_range(struct coredump_params *cprm, unsigned long start, unsigned long len); extern void do_coredump(const kernel_siginfo_t *siginfo); + +/* + * Logging for the coredump code, ratelimited. + * The TGID and comm fields are added to the message. + */ + +#define __COREDUMP_PRINTK(Level, Format, ...) \ + do { \ + char comm[TASK_COMM_LEN]; \ + \ + get_task_comm(comm, current); \ + printk_ratelimited(Level "coredump: %d(%*pE): " Format "\n", \ + task_tgid_vnr(current), (int)strlen(comm), comm, ##__VA_ARGS__); \ + } while (0) \ + +#define coredump_report(fmt, ...) __COREDUMP_PRINTK(KERN_INFO, fmt, ##__VA_ARGS__) +#define coredump_report_failure(fmt, ...) __COREDUMP_PRINTK(KERN_WARNING, fmt, ##__VA_ARGS__) + #else static inline void do_coredump(const kernel_siginfo_t *siginfo) {} + +#define coredump_report(...) +#define coredump_report_failure(...) + #endif #if defined(CONFIG_COREDUMP) && defined(CONFIG_SYSCTL) -- 2.43.0