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path: root/drivers/tty/tty_audit.c
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2020-11-06tty: tty_audit: Demote non-conformant kernel-doc headersLee Jones
Fixes the following W=1 kernel build warning(s): drivers/tty/tty_audit.c:91: warning: Function parameter or member 'buf' not described in 'tty_audit_buf_push' drivers/tty/tty_audit.c:129: warning: Function parameter or member 'sig' not described in 'tty_audit_fork' drivers/tty/tty_audit.c:137: warning: Function parameter or member 'tty' not described in 'tty_audit_tiocsti' drivers/tty/tty_audit.c:137: warning: Function parameter or member 'ch' not described in 'tty_audit_tiocsti' drivers/tty/tty_audit.c:202: warning: Function parameter or member 'tty' not described in 'tty_audit_add_data' drivers/tty/tty_audit.c:202: warning: Function parameter or member 'data' not described in 'tty_audit_add_data' drivers/tty/tty_audit.c:202: warning: Function parameter or member 'size' not described in 'tty_audit_add_data' Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Miloslav Trmac <mitr@redhat.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20201104193549.4026187-16-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-07audit: join tty records to their syscallRichard Guy Briggs
AUDIT_TTY records were logged as seperate events from their syscall records. Join them so they are logged as the single event that they are. Please see the github issue https://github.com/linux-audit/audit-kernel/issues/106 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-11-26audit: use current whenever possiblePaul Moore
There are many places, notably audit_log_task_info() and audit_log_exit(), that take task_struct pointers but in reality they are always working on the current task. This patch eliminates the task_struct arguments and uses current directly which allows a number of cleanups as well. Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-06-19audit: eliminate audit_enabled magic number comparisonRichard Guy Briggs
Remove comparison of audit_enabled to magic numbers outside of audit. Related: https://github.com/linux-audit/audit-kernel/issues/86 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-11-08tty: Remove redundant license textGreg Kroah-Hartman
Now that the SPDX tag is in all tty files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Jiri Slaby <jslaby@suse.com> Cc: James Hogan <jhogan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-07tty: audit: remove unused variableSudip Mukherjee
While building with W=1 we were getting build warning: drivers/tty/tty_audit.c:149:16: warning: variable 'sessionid' set but not used The local variable sessionid was only assigned the value of current->sessionid but was never reused. On further inspection it turned out that there is no need of audit_get_loginuid() also. Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Poison tty_audit_buf while process exitsPeter Hurley
Warn if tty_audit_buf use is attempted after tty_audit_exit() has already freed it. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Always push audit buffer before TIOCSTIPeter Hurley
The data read from another tty may be relevant to the action of the TIOCSTI ioctl; log the audit buffer immediately. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Check audit enable firstPeter Hurley
Audit is unlikely to be enabled; check first to exit asap. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Simplify first-use allocationPeter Hurley
The first-use tty audit buffer allocation is a potential race amongst multiple attempts at 'first-use'; only one 'winner' is acceptable. The successful buffer assignment occurs if tty_audit_buf == NULL (which will also be the return from cmpxchg()); otherwise, another racer 'won' and this buffer allocation is freed. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Remove tty_audit_buf reference countingPeter Hurley
When tty_audit_exit() is called from do_exit(), the process is single-threaded. Since the tty_audit_buf is only shared by threads of a process, no other thread can be concurrently accessing the tty_audit_buf during or after tty_audit_exit(). Thus, no other thread can be holding an extra tty_audit_buf reference which would prevent tty_audit_exit() from freeing the tty_audit_buf. As that is the only purpose of the ref counting, remove the reference counting and free the tty_audit_buf directly. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Remove false memory optimizationPeter Hurley
The tty audit buffer is allocated at first use and not freed until the process exits. If tty audit is turned off after the audit buffer has been allocated, no effort is made to release the buffer. So re-checking if tty audit has just been turned off when tty audit was just on is false optimization; the likelihood of triggering this condition is exceedingly small. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Handle tty audit enable atomicallyPeter Hurley
The audit_tty and audit_tty_log_passwd fields are actually bool values, so merge into single memory location to access atomically. NB: audit log operations may still occur after tty audit is disabled which is consistent with the existing functionality Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Track tty association with dev_tPeter Hurley
Use dev_t instead of separate major/minor fields to track tty audit buffer association. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Combine push functionsPeter Hurley
tty_audit_push() and tty_audit_push_current() perform identical tasks; eliminate the tty_audit_push() implementation and the tty_audit_push_current() name. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Ignore current association for audit pushPeter Hurley
In canonical read mode, each line read and logged is pushed separately with tty_audit_push(). For all single-threaded processes and multi-threaded processes reading from only one tty, this patch has no effect; the last line read will still be the entry pushed to the audit log because the tty association cannot have changed between tty_audit_add_data() and tty_audit_push(). For multi-threaded processes reading from different ttys concurrently, the audit log will have mixed log entries anyway. Consider two ttys audited concurrently: CPU0 CPU1 ---------- ------------ tty_audit_add_data(ttyA) tty_audit_add_data(ttyB) tty_audit_push() tty_audit_add_data(ttyB) tty_audit_push() This patch will now cause the ttyB output to be split into separate audit log entries. However, this possibility is equally likely without this patch: CPU0 CPU1 ---------- ------------ tty_audit_add_data(ttyB) tty_audit_add_data(ttyA) tty_audit_push() tty_audit_add_data(ttyB) tty_audit_push() Mixed canonical and non-canonical reads have similar races. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Take siglock directlyPeter Hurley
lock_task_sighand() is for situations where the struct task_struct* may disappear while trying to deref the sighand; this never applies to 'current'. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Defer audit buffer associationPeter Hurley
The tty audit buffer used to audit/record tty input is allocated on the process's first call to tty_audit_add_data(), and not freed until the process exits. On each call to tty_audit_add_data(), the current tty is compared (by major:minor) with the last tty associated with the audit buffer, and if the tty has changed the existing data is logged to the audit log. The audit buffer is then re-associated with the new tty. Currently, the audit buffer is immediately associated with the tty; however, the association must be re-checked when the buffer is locked prior to copying the tty input. This extra step is always necessary, since a concurrent read of a different tty by another thread of the process may have used the buffer in between allocation and buffer lock. Rather than associate the audit buffer with the tty at allocation, leave the buffer initially un-associated (null dev_t); simply let the re-association check also perform the initial association. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Remove icanon mode from call chainPeter Hurley
The tty termios bits cannot change while n_tty_read() is in the i/o loop; the termios_rwsem ensures mutual exclusion with termios changes in n_tty_set_termios(). Check L_ICANON() directly and eliminate icanon parameter. NB: tty_audit_add_data() => tty_audit_buf_get() => tty_audit_buf_alloc() is a single path; ie., tty_audit_buf_get() and tty_audit_buf_alloc() have no other callers. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: audit: Early-out pty master reads earlierPeter Hurley
Reads from pty masters are not logged; early-out before taking locks. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20tty: audit: Fix audit sourcePeter Hurley
The data to audit/record is in the 'from' buffer (ie., the input read buffer). Fixes: 72586c6061ab ("n_tty: Fix auditing support for cannonical mode") Cc: stable <stable@vger.kernel.org> # 4.1+ Cc: Miloslav Trmač <mitr@redhat.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-20audit: anchor all pid references in the initial pid namespaceRichard Guy Briggs
Store and log all PIDs with reference to the initial PID namespace and use the access functions task_pid_nr() and task_tgid_nr() for task->pid and task->tgid. Cc: "Eric W. Biederman" <ebiederm@xmission.com> (informed by ebiederman's c776b5d2) Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
2014-01-13audit: convert all sessionid declaration to unsigned intEric Paris
Right now the sessionid value in the kernel is a combination of u32, int, and unsigned int. Just use unsigned int throughout. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-30audit: do not needlessly take a lock in tty_audit_exitEric Paris
We were doing spin_lock_irq and spin_unlock_irq. This is STOOPID. If we were in interupt context we were already screwed and called panic() in do_exit(). So the irq stuff is useless. Also, these values can only be changed by receiving a netlink message from current. Since we are in do_exit() clearly we aren't in the syscall sending the netlink message to change these values. Thus, just read them and go with it. Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-30audit: do not needlessly take a spinlock in copy_signalEric Paris
current->signal->audit_* can only change from a netlink message from current. Obviously in this case we cannot be handling a netlink message from current. So there is no change these can change under us. No need to take a lock to read them. Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-30audit: add an option to control logging of passwords with pam_tty_auditRichard Guy Briggs
Most commands are entered one line at a time and processed as complete lines in non-canonical mode. Commands that interactively require a password, enter canonical mode to do this while shutting off echo. This pair of features (icanon and !echo) can be used to avoid logging passwords by audit while still logging the rest of the command. Adding a member (log_passwd) to the struct audit_tty_status passed in by pam_tty_audit allows control of canonical mode without echo per task. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-30audit: use spin_lock_irqsave/restore in audit tty codeEric Paris
Some of the callers of the audit tty function use spin_lock_irqsave/restore. We were using the forced always enable version, which seems really bad. Since I don't know every one of these code paths well enough, it makes sense to just switch everything to the safe version. Maybe it's a little overzealous, but it's a lot better than an unlucky deadlock when we return to a caller with irq enabled and they expect it to be disabled. Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-30audit: push loginuid and sessionid processing downEric Paris
Since we are always current, we can push a lot of this stuff to the bottom and get rid of useless interfaces and arguments. Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-30audit: stop pushing loginid, uid, sessionid as argumentsEric Paris
We always use current. Stop pulling this when the skb comes in and pushing it around as arguments. Just get it at the end when you need it. Signed-off-by: Eric Paris <eparis@redhat.com>
2012-10-22TTY: audit, stop accessing tty->icountJiri Slaby
This is a private member of n_tty. Stop accessing it. Instead, take is as an argument. This is needed to allow clean switch of the private members to a separate private structure of n_tty. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-18userns: Convert audit to work with user namespaces enabledEric W. Biederman
- Explicitly format uids gids in audit messges in the initial user namespace. This is safe because auditd is restrected to be in the initial user namespace. - Convert audit_sig_uid into a kuid_t. - Enable building the audit code and user namespaces at the same time. The net result is that the audit subsystem now uses kuid_t and kgid_t whenever possible making it almost impossible to confuse a raw uid_t with a kuid_t preventing bugs. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-17userns: Convert the audit loginuid to be a kuidEric W. Biederman
Always store audit loginuids in type kuid_t. Print loginuids by converting them into uids in the appropriate user namespace, and then printing the resulting uid. Modify audit_get_loginuid to return a kuid_t. Modify audit_set_loginuid to take a kuid_t. Modify /proc/<pid>/loginuid on read to convert the loginuid into the user namespace of the opener of the file. Modify /proc/<pid>/loginud on write to convert the loginuid rom the user namespace of the opener of the file. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Paul Moore <paul@paul-moore.com> ? Cc: David Miller <davem@davemloft.net> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-03-07tty_audit: fix tty_audit_add_data live lock on audit disabledXiaotian Feng
The current tty_audit_add_data code: do { size_t run; run = N_TTY_BUF_SIZE - buf->valid; if (run > size) run = size; memcpy(buf->data + buf->valid, data, run); buf->valid += run; data += run; size -= run; if (buf->valid == N_TTY_BUF_SIZE) tty_audit_buf_push_current(buf); } while (size != 0); If the current buffer is full, kernel will then call tty_audit_buf_push_current to empty the buffer. But if we disabled audit at the same time, tty_audit_buf_push() returns immediately if audit_enabled is zero. Without emptying the buffer. With obvious effect on tty_audit_add_data() that ends up spinning in that loop, copying 0 bytes at each iteration and attempting to push each time without any effect. Holding the lock all along. Suggested-by: Alexander Viro <aviro@redhat.com> Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-05TTY: create drivers/tty and move the tty core files thereGreg Kroah-Hartman
The tty code should be in its own subdirectory and not in the char driver with all of the cruft that is currently there. Based on work done by Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>