diff options
author | Kees Cook <keescook@chromium.org> | 2017-02-14 01:25:26 +0100 |
---|---|---|
committer | Jens Axboe <axboe@fb.com> | 2017-02-14 16:29:56 +0100 |
commit | 853fe1bf7554155376bb3b231112cdff9ff79177 (patch) | |
tree | 7d8b38a77574919d078443cecffcae9dd380a692 /drivers/cdrom/cdrom.c | |
parent | elevator: fix loading wrong elevator type for blk-mq devices (diff) | |
download | linux-853fe1bf7554155376bb3b231112cdff9ff79177.tar.xz linux-853fe1bf7554155376bb3b231112cdff9ff79177.zip |
cdrom: Make device operations read-only
Since function tables are a common target for attackers, it's best to keep
them in read-only memory. As such, this makes the CDROM device ops tables
const. This drops additionally n_minors, since it isn't used meaningfully,
and sets the only user of cdrom_dummy_generic_packet explicitly so the
variables can all be const.
Inspired by similar changes in grsecurity/PaX.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/cdrom/cdrom.c')
-rw-r--r-- | drivers/cdrom/cdrom.c | 58 |
1 files changed, 28 insertions, 30 deletions
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index 59cca72647a6..bbbd3caa927c 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -342,8 +342,8 @@ static void cdrom_sysctl_register(void); static LIST_HEAD(cdrom_list); -static int cdrom_dummy_generic_packet(struct cdrom_device_info *cdi, - struct packet_command *cgc) +int cdrom_dummy_generic_packet(struct cdrom_device_info *cdi, + struct packet_command *cgc) { if (cgc->sense) { cgc->sense->sense_key = 0x05; @@ -354,6 +354,7 @@ static int cdrom_dummy_generic_packet(struct cdrom_device_info *cdi, cgc->stat = -EIO; return -EIO; } +EXPORT_SYMBOL(cdrom_dummy_generic_packet); static int cdrom_flush_cache(struct cdrom_device_info *cdi) { @@ -371,7 +372,7 @@ static int cdrom_flush_cache(struct cdrom_device_info *cdi) static int cdrom_get_disc_info(struct cdrom_device_info *cdi, disc_information *di) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; struct packet_command cgc; int ret, buflen; @@ -586,7 +587,7 @@ static int cdrom_mrw_set_lba_space(struct cdrom_device_info *cdi, int space) int register_cdrom(struct cdrom_device_info *cdi) { static char banner_printed; - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; int *change_capability = (int *)&cdo->capability; /* hack */ cd_dbg(CD_OPEN, "entering register_cdrom\n"); @@ -610,7 +611,6 @@ int register_cdrom(struct cdrom_device_info *cdi) ENSURE(reset, CDC_RESET); ENSURE(generic_packet, CDC_GENERIC_PACKET); cdi->mc_flags = 0; - cdo->n_minors = 0; cdi->options = CDO_USE_FFLAGS; if (autoclose == 1 && CDROM_CAN(CDC_CLOSE_TRAY)) @@ -630,8 +630,7 @@ int register_cdrom(struct cdrom_device_info *cdi) else cdi->cdda_method = CDDA_OLD; - if (!cdo->generic_packet) - cdo->generic_packet = cdrom_dummy_generic_packet; + WARN_ON(!cdo->generic_packet); cd_dbg(CD_REG_UNREG, "drive \"/dev/%s\" registered\n", cdi->name); mutex_lock(&cdrom_mutex); @@ -652,7 +651,6 @@ void unregister_cdrom(struct cdrom_device_info *cdi) if (cdi->exit) cdi->exit(cdi); - cdi->ops->n_minors--; cd_dbg(CD_REG_UNREG, "drive \"/dev/%s\" unregistered\n", cdi->name); } @@ -1036,7 +1034,7 @@ static int open_for_data(struct cdrom_device_info *cdi) { int ret; - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; tracktype tracks; cd_dbg(CD_OPEN, "entering open_for_data\n"); /* Check if the driver can report drive status. If it can, we @@ -1198,8 +1196,8 @@ err: /* This code is similar to that in open_for_data. The routine is called whenever an audio play operation is requested. */ -static int check_for_audio_disc(struct cdrom_device_info * cdi, - struct cdrom_device_ops * cdo) +static int check_for_audio_disc(struct cdrom_device_info *cdi, + const struct cdrom_device_ops *cdo) { int ret; tracktype tracks; @@ -1254,7 +1252,7 @@ static int check_for_audio_disc(struct cdrom_device_info * cdi, void cdrom_release(struct cdrom_device_info *cdi, fmode_t mode) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; int opened_for_data; cd_dbg(CD_CLOSE, "entering cdrom_release\n"); @@ -1294,7 +1292,7 @@ static int cdrom_read_mech_status(struct cdrom_device_info *cdi, struct cdrom_changer_info *buf) { struct packet_command cgc; - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; int length; /* @@ -1643,7 +1641,7 @@ static int dvd_do_auth(struct cdrom_device_info *cdi, dvd_authinfo *ai) int ret; u_char buf[20]; struct packet_command cgc; - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; rpc_state_t rpc_state; memset(buf, 0, sizeof(buf)); @@ -1791,7 +1789,7 @@ static int dvd_read_physical(struct cdrom_device_info *cdi, dvd_struct *s, { unsigned char buf[21], *base; struct dvd_layer *layer; - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; int ret, layer_num = s->physical.layer_num; if (layer_num >= DVD_LAYERS) @@ -1842,7 +1840,7 @@ static int dvd_read_copyright(struct cdrom_device_info *cdi, dvd_struct *s, { int ret; u_char buf[8]; - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; init_cdrom_command(cgc, buf, sizeof(buf), CGC_DATA_READ); cgc->cmd[0] = GPCMD_READ_DVD_STRUCTURE; @@ -1866,7 +1864,7 @@ static int dvd_read_disckey(struct cdrom_device_info *cdi, dvd_struct *s, { int ret, size; u_char *buf; - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; size = sizeof(s->disckey.value) + 4; @@ -1894,7 +1892,7 @@ static int dvd_read_bca(struct cdrom_device_info *cdi, dvd_struct *s, { int ret, size = 4 + 188; u_char *buf; - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; buf = kmalloc(size, GFP_KERNEL); if (!buf) @@ -1928,7 +1926,7 @@ static int dvd_read_manufact(struct cdrom_device_info *cdi, dvd_struct *s, { int ret = 0, size; u_char *buf; - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; size = sizeof(s->manufact.value) + 4; @@ -1995,7 +1993,7 @@ int cdrom_mode_sense(struct cdrom_device_info *cdi, struct packet_command *cgc, int page_code, int page_control) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; memset(cgc->cmd, 0, sizeof(cgc->cmd)); @@ -2010,7 +2008,7 @@ int cdrom_mode_sense(struct cdrom_device_info *cdi, int cdrom_mode_select(struct cdrom_device_info *cdi, struct packet_command *cgc) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; memset(cgc->cmd, 0, sizeof(cgc->cmd)); memset(cgc->buffer, 0, 2); @@ -2025,7 +2023,7 @@ int cdrom_mode_select(struct cdrom_device_info *cdi, static int cdrom_read_subchannel(struct cdrom_device_info *cdi, struct cdrom_subchnl *subchnl, int mcn) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; struct packet_command cgc; char buffer[32]; int ret; @@ -2073,7 +2071,7 @@ static int cdrom_read_cd(struct cdrom_device_info *cdi, struct packet_command *cgc, int lba, int blocksize, int nblocks) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; memset(&cgc->cmd, 0, sizeof(cgc->cmd)); cgc->cmd[0] = GPCMD_READ_10; @@ -2093,7 +2091,7 @@ static int cdrom_read_block(struct cdrom_device_info *cdi, struct packet_command *cgc, int lba, int nblocks, int format, int blksize) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; memset(&cgc->cmd, 0, sizeof(cgc->cmd)); cgc->cmd[0] = GPCMD_READ_CD; @@ -2764,7 +2762,7 @@ static int cdrom_ioctl_audioctl(struct cdrom_device_info *cdi, */ static int cdrom_switch_blocksize(struct cdrom_device_info *cdi, int size) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; struct packet_command cgc; struct modesel_head mh; @@ -2790,7 +2788,7 @@ static int cdrom_switch_blocksize(struct cdrom_device_info *cdi, int size) static int cdrom_get_track_info(struct cdrom_device_info *cdi, __u16 track, __u8 type, track_information *ti) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; struct packet_command cgc; int ret, buflen; @@ -3049,7 +3047,7 @@ static noinline int mmc_ioctl_cdrom_play_msf(struct cdrom_device_info *cdi, void __user *arg, struct packet_command *cgc) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; struct cdrom_msf msf; cd_dbg(CD_DO_IOCTL, "entering CDROMPLAYMSF\n"); if (copy_from_user(&msf, (struct cdrom_msf __user *)arg, sizeof(msf))) @@ -3069,7 +3067,7 @@ static noinline int mmc_ioctl_cdrom_play_blk(struct cdrom_device_info *cdi, void __user *arg, struct packet_command *cgc) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; struct cdrom_blk blk; cd_dbg(CD_DO_IOCTL, "entering CDROMPLAYBLK\n"); if (copy_from_user(&blk, (struct cdrom_blk __user *)arg, sizeof(blk))) @@ -3164,7 +3162,7 @@ static noinline int mmc_ioctl_cdrom_start_stop(struct cdrom_device_info *cdi, struct packet_command *cgc, int cmd) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; cd_dbg(CD_DO_IOCTL, "entering CDROMSTART/CDROMSTOP\n"); cgc->cmd[0] = GPCMD_START_STOP_UNIT; cgc->cmd[1] = 1; @@ -3177,7 +3175,7 @@ static noinline int mmc_ioctl_cdrom_pause_resume(struct cdrom_device_info *cdi, struct packet_command *cgc, int cmd) { - struct cdrom_device_ops *cdo = cdi->ops; + const struct cdrom_device_ops *cdo = cdi->ops; cd_dbg(CD_DO_IOCTL, "entering CDROMPAUSE/CDROMRESUME\n"); cgc->cmd[0] = GPCMD_PAUSE_RESUME; cgc->cmd[8] = (cmd == CDROMRESUME) ? 1 : 0; |