Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 08e2fb6c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux 

Pull pstore fixes from Tony Luck:
 "On a system that restricts access to dmesg, don't let people side-step
  that by reading copies that pstore saved"

* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  syslog: Provide stub check_syslog_permissions
  pstore: Honor dmesg_restrict sysctl on dmesg dumps
  pstore/ram: Strip ramoops header for correct decompression
parents e20db597 069fb0b6

fs/pstore/inode.c

+22 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 
#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/uaccess.h>

#include <linux/syslog.h>



#include "internal.h"
@@ -120,6 +121,18 @@ static const struct seq_operations pstore_ftrace_seq_ops = { 
	.show	= pstore_ftrace_seq_show,

};



static int pstore_check_syslog_permissions(struct pstore_private *ps)

{

	switch (ps->type) {

	case PSTORE_TYPE_DMESG:

	case PSTORE_TYPE_CONSOLE:

		return check_syslog_permissions(SYSLOG_ACTION_READ_ALL,

			SYSLOG_FROM_READER);

	default:

		return 0;

	}

}



static ssize_t pstore_file_read(struct file *file, char __user *userbuf,

						size_t count, loff_t *ppos)

{
@@ -138,6 +151,10 @@ static int pstore_file_open(struct inode *inode, struct file *file) 
	int err;

	const struct seq_operations *sops = NULL;



	err = pstore_check_syslog_permissions(ps);

	if (err)

		return err;



	if (ps->type == PSTORE_TYPE_FTRACE)

		sops = &pstore_ftrace_seq_ops;
@@ -174,6 +191,11 @@ static const struct file_operations pstore_file_operations = { 
static int pstore_unlink(struct inode *dir, struct dentry *dentry)

{

	struct pstore_private *p = dentry->d_inode->i_private;

	int err;



	err = pstore_check_syslog_permissions(p);

	if (err)

		return err;



	if (p->psi->erase)

		p->psi->erase(p->type, p->id, p->count,

fs/pstore/ram.c

+15 −7
Original line number Diff line number Diff line
@@ -135,25 +135,27 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max, 
	return prz;

}



static void ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,

static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,

				  bool *compressed)

{

	char data_type;

	int header_length = 0;



	if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",

			&time->tv_sec, &time->tv_nsec, &data_type) == 3) {

	if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,

			&time->tv_nsec, &data_type, &header_length) == 3) {

		if (data_type == 'C')

			*compressed = true;

		else

			*compressed = false;

	} else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",

			&time->tv_sec, &time->tv_nsec) == 2) {

	} else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",

			&time->tv_sec, &time->tv_nsec, &header_length) == 2) {

			*compressed = false;

	} else {

		time->tv_sec = 0;

		time->tv_nsec = 0;

		*compressed = false;

	}

	return header_length;

}



static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
@@ -165,6 +167,7 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, 
	ssize_t ecc_notice_size;

	struct ramoops_context *cxt = psi->data;

	struct persistent_ram_zone *prz;

	int header_length;



	prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,

				   cxt->max_dump_cnt, id, type,
@@ -178,7 +181,13 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, 
	if (!prz)

		return 0;



	if (!persistent_ram_old(prz))

		return 0;



	size = persistent_ram_old_size(prz);

	header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), time,

			compressed);

	size -= header_length;



	/* ECC correction notice */

	ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
@@ -187,8 +196,7 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, 
	if (*buf == NULL)

		return -ENOMEM;



	memcpy(*buf, persistent_ram_old(prz), size);

	ramoops_read_kmsg_hdr(*buf, time, compressed);

	memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);

	persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1);



	return size + ecc_notice_size;

include/linux/syslog.h

+9 −0
Original line number Diff line number Diff line
@@ -49,4 +49,13 @@ 


int do_syslog(int type, char __user *buf, int count, bool from_file);



#ifdef CONFIG_PRINTK

int check_syslog_permissions(int type, bool from_file);

#else

static inline int check_syslog_permissions(int type, bool from_file)

{

	return 0;

}

#endif



#endif /* _LINUX_SYSLOG_H */

kernel/printk/printk.c

+1 −1
Original line number Diff line number Diff line
@@ -480,7 +480,7 @@ static int syslog_action_restricted(int type) 
	       type != SYSLOG_ACTION_SIZE_BUFFER;

}



static int check_syslog_permissions(int type, bool from_file)

int check_syslog_permissions(int type, bool from_file)

{

	/*

	 * If this is from /proc/kmsg and we've already opened it, then we've