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FAILED: patch "[PATCH] CIFS: Increment num_remote_opens stats counter even in case" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1be1fa42ebb73ad8fd67d2c846931361b4e3dd0a Mon Sep 17 00:00:00 2001 From: Shyam Prasad N <nspmangalore(a)gmail.com> Date: Mon, 9 Mar 2020 01:35:09 -0700 Subject: [PATCH] CIFS: Increment num_remote_opens stats counter even in case of smb2_query_dir_first The num_remote_opens counter keeps track of the number of open files which must be maintained by the server at any point. This is a per-tree-connect counter, and the value of this counter gets displayed in the /proc/fs/cifs/Stats output as a following... Open files: 0 total (local), 1 open on server ^^^^^^^^^^^^^^^^ As a thumb-rule, we want to increment this counter for each open/create that we successfully execute on the server. Similarly, we should decrement the counter when we successfully execute a close. In this case, an increment was being missed in case of smb2_query_dir_first, in case of successful open. As a result, we would underflow the counter and we could even see the counter go to negative after sufficient smb2_query_dir_first calls. I tested the stats counter for a bunch of filesystem operations with the fix. And it looks like the counter looks correct to me. I also check if we missed the increments and decrements elsewhere. It does not seem so. Few other cases where an open is done and we don't increment the counter are the compound calls where the corresponding close is also sent in the request. Signed-off-by: Shyam Prasad N <nspmangalore(a)gmail.com> CC: Stable <stable(a)vger.kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> Reviewed-by: Aurelien Aptel <aaptel(a)suse.com> Reviewed-by: Pavel Shilovsky <pshilov(a)microsoft.com> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index c31e84ee3c39..3dddd20c5e2b 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2222,6 +2222,8 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, goto qdf_free; } + atomic_inc(&tcon->num_remote_opens); + qd_rsp = (struct smb2_query_directory_rsp *)rsp_iov[1].iov_base; if (qd_rsp->sync_hdr.Status == STATUS_NO_MORE_FILES) { trace_smb3_query_dir_done(xid, fid->persistent_fid,

5 years, 7 months

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FAILED: patch "[PATCH] CIFS: Increment num_remote_opens stats counter even in case" failed to apply to 5.5-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.5-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1be1fa42ebb73ad8fd67d2c846931361b4e3dd0a Mon Sep 17 00:00:00 2001 From: Shyam Prasad N <nspmangalore(a)gmail.com> Date: Mon, 9 Mar 2020 01:35:09 -0700 Subject: [PATCH] CIFS: Increment num_remote_opens stats counter even in case of smb2_query_dir_first The num_remote_opens counter keeps track of the number of open files which must be maintained by the server at any point. This is a per-tree-connect counter, and the value of this counter gets displayed in the /proc/fs/cifs/Stats output as a following... Open files: 0 total (local), 1 open on server ^^^^^^^^^^^^^^^^ As a thumb-rule, we want to increment this counter for each open/create that we successfully execute on the server. Similarly, we should decrement the counter when we successfully execute a close. In this case, an increment was being missed in case of smb2_query_dir_first, in case of successful open. As a result, we would underflow the counter and we could even see the counter go to negative after sufficient smb2_query_dir_first calls. I tested the stats counter for a bunch of filesystem operations with the fix. And it looks like the counter looks correct to me. I also check if we missed the increments and decrements elsewhere. It does not seem so. Few other cases where an open is done and we don't increment the counter are the compound calls where the corresponding close is also sent in the request. Signed-off-by: Shyam Prasad N <nspmangalore(a)gmail.com> CC: Stable <stable(a)vger.kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> Reviewed-by: Aurelien Aptel <aaptel(a)suse.com> Reviewed-by: Pavel Shilovsky <pshilov(a)microsoft.com> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index c31e84ee3c39..3dddd20c5e2b 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2222,6 +2222,8 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, goto qdf_free; } + atomic_inc(&tcon->num_remote_opens); + qd_rsp = (struct smb2_query_directory_rsp *)rsp_iov[1].iov_base; if (qd_rsp->sync_hdr.Status == STATUS_NO_MORE_FILES) { trace_smb3_query_dir_done(xid, fid->persistent_fid,

5 years, 7 months

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FAILED: patch "[PATCH] USB: cdc-acm: fix close_delay and closing_wait units in" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 633e2b2ded739a34bd0fb1d8b5b871f7e489ea29 Mon Sep 17 00:00:00 2001 From: Anthony Mallet <anthony.mallet(a)laas.fr> Date: Thu, 12 Mar 2020 14:31:00 +0100 Subject: [PATCH] USB: cdc-acm: fix close_delay and closing_wait units in TIOCSSERIAL close_delay and closing_wait are specified in hundredth of a second but stored internally in jiffies. Use the jiffies_to_msecs() and msecs_to_jiffies() functions to convert from each other. Signed-off-by: Anthony Mallet <anthony.mallet(a)laas.fr> Cc: stable <stable(a)vger.kernel.org> Link: https://lore.kernel.org/r/20200312133101.7096-1-anthony.mallet@laas.fr Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 62f4fb9b362f..da619176deca 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -896,10 +896,10 @@ static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss) ss->xmit_fifo_size = acm->writesize; ss->baud_base = le32_to_cpu(acm->line.dwDTERate); - ss->close_delay = acm->port.close_delay / 10; + ss->close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; ss->closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE : - acm->port.closing_wait / 10; + jiffies_to_msecs(acm->port.closing_wait) / 10; return 0; } @@ -909,9 +909,10 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) unsigned int closing_wait, close_delay; int retval = 0; - close_delay = ss->close_delay * 10; + close_delay = msecs_to_jiffies(ss->close_delay * 10); closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ? - ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10; + ASYNC_CLOSING_WAIT_NONE : + msecs_to_jiffies(ss->closing_wait * 10); mutex_lock(&acm->port.mutex);

5 years, 7 months

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FAILED: patch "[PATCH] USB: cdc-acm: fix close_delay and closing_wait units in" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 633e2b2ded739a34bd0fb1d8b5b871f7e489ea29 Mon Sep 17 00:00:00 2001 From: Anthony Mallet <anthony.mallet(a)laas.fr> Date: Thu, 12 Mar 2020 14:31:00 +0100 Subject: [PATCH] USB: cdc-acm: fix close_delay and closing_wait units in TIOCSSERIAL close_delay and closing_wait are specified in hundredth of a second but stored internally in jiffies. Use the jiffies_to_msecs() and msecs_to_jiffies() functions to convert from each other. Signed-off-by: Anthony Mallet <anthony.mallet(a)laas.fr> Cc: stable <stable(a)vger.kernel.org> Link: https://lore.kernel.org/r/20200312133101.7096-1-anthony.mallet@laas.fr Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 62f4fb9b362f..da619176deca 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -896,10 +896,10 @@ static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss) ss->xmit_fifo_size = acm->writesize; ss->baud_base = le32_to_cpu(acm->line.dwDTERate); - ss->close_delay = acm->port.close_delay / 10; + ss->close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; ss->closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE : - acm->port.closing_wait / 10; + jiffies_to_msecs(acm->port.closing_wait) / 10; return 0; } @@ -909,9 +909,10 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) unsigned int closing_wait, close_delay; int retval = 0; - close_delay = ss->close_delay * 10; + close_delay = msecs_to_jiffies(ss->close_delay * 10); closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ? - ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10; + ASYNC_CLOSING_WAIT_NONE : + msecs_to_jiffies(ss->closing_wait * 10); mutex_lock(&acm->port.mutex);

5 years, 7 months

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FAILED: patch "[PATCH] USB: cdc-acm: fix close_delay and closing_wait units in" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 633e2b2ded739a34bd0fb1d8b5b871f7e489ea29 Mon Sep 17 00:00:00 2001 From: Anthony Mallet <anthony.mallet(a)laas.fr> Date: Thu, 12 Mar 2020 14:31:00 +0100 Subject: [PATCH] USB: cdc-acm: fix close_delay and closing_wait units in TIOCSSERIAL close_delay and closing_wait are specified in hundredth of a second but stored internally in jiffies. Use the jiffies_to_msecs() and msecs_to_jiffies() functions to convert from each other. Signed-off-by: Anthony Mallet <anthony.mallet(a)laas.fr> Cc: stable <stable(a)vger.kernel.org> Link: https://lore.kernel.org/r/20200312133101.7096-1-anthony.mallet@laas.fr Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 62f4fb9b362f..da619176deca 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -896,10 +896,10 @@ static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss) ss->xmit_fifo_size = acm->writesize; ss->baud_base = le32_to_cpu(acm->line.dwDTERate); - ss->close_delay = acm->port.close_delay / 10; + ss->close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; ss->closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE : - acm->port.closing_wait / 10; + jiffies_to_msecs(acm->port.closing_wait) / 10; return 0; } @@ -909,9 +909,10 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) unsigned int closing_wait, close_delay; int retval = 0; - close_delay = ss->close_delay * 10; + close_delay = msecs_to_jiffies(ss->close_delay * 10); closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ? - ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10; + ASYNC_CLOSING_WAIT_NONE : + msecs_to_jiffies(ss->closing_wait * 10); mutex_lock(&acm->port.mutex);

5 years, 7 months

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FAILED: patch "[PATCH] USB: cdc-acm: fix rounding error in TIOCSSERIAL" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b401f8c4f492cbf74f3f59c9141e5be3071071bb Mon Sep 17 00:00:00 2001 From: Anthony Mallet <anthony.mallet(a)laas.fr> Date: Thu, 12 Mar 2020 14:31:01 +0100 Subject: [PATCH] USB: cdc-acm: fix rounding error in TIOCSSERIAL By default, tty_port_init() initializes those parameters to a multiple of HZ. For instance in line 69 of tty_port.c: port->close_delay = (50 * HZ) / 100; https://github.com/torvalds/linux/blob/master/drivers/tty/tty_port.c#L69 With e.g. CONFIG_HZ = 250 (as this is the case for Ubuntu 18.04 linux-image-4.15.0-37-generic), the default setting for close_delay is thus 125. When ioctl(fd, TIOCGSERIAL, &s) is executed, the setting returned in user space is '12' (125/10). When ioctl(fd, TIOCSSERIAL, &s) is then executed with the same setting '12', the value is interpreted as '120' which is different from the current setting and a EPERM error may be raised by set_serial_info() if !CAP_SYS_ADMIN. https://github.com/torvalds/linux/blob/master/drivers/usb/class/cdc-acm.c#L… Fixes: ba2d8ce9db0a6 ("cdc-acm: implement TIOCSSERIAL to avoid blocking close(2)") Signed-off-by: Anthony Mallet <anthony.mallet(a)laas.fr> Cc: stable <stable(a)vger.kernel.org> Link: https://lore.kernel.org/r/20200312133101.7096-2-anthony.mallet@laas.fr Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index da619176deca..47f09a6ce7bd 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -907,6 +907,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) { struct acm *acm = tty->driver_data; unsigned int closing_wait, close_delay; + unsigned int old_closing_wait, old_close_delay; int retval = 0; close_delay = msecs_to_jiffies(ss->close_delay * 10); @@ -914,18 +915,24 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) ASYNC_CLOSING_WAIT_NONE : msecs_to_jiffies(ss->closing_wait * 10); + /* we must redo the rounding here, so that the values match */ + old_close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; + old_closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? + ASYNC_CLOSING_WAIT_NONE : + jiffies_to_msecs(acm->port.closing_wait) / 10; + mutex_lock(&acm->port.mutex); - if (!capable(CAP_SYS_ADMIN)) { - if ((close_delay != acm->port.close_delay) || - (closing_wait != acm->port.closing_wait)) + if ((ss->close_delay != old_close_delay) || + (ss->closing_wait != old_closing_wait)) { + if (!capable(CAP_SYS_ADMIN)) retval = -EPERM; - else - retval = -EOPNOTSUPP; - } else { - acm->port.close_delay = close_delay; - acm->port.closing_wait = closing_wait; - } + else { + acm->port.close_delay = close_delay; + acm->port.closing_wait = closing_wait; + } + } else + retval = -EOPNOTSUPP; mutex_unlock(&acm->port.mutex); return retval;

5 years, 7 months

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FAILED: patch "[PATCH] USB: cdc-acm: fix rounding error in TIOCSSERIAL" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b401f8c4f492cbf74f3f59c9141e5be3071071bb Mon Sep 17 00:00:00 2001 From: Anthony Mallet <anthony.mallet(a)laas.fr> Date: Thu, 12 Mar 2020 14:31:01 +0100 Subject: [PATCH] USB: cdc-acm: fix rounding error in TIOCSSERIAL By default, tty_port_init() initializes those parameters to a multiple of HZ. For instance in line 69 of tty_port.c: port->close_delay = (50 * HZ) / 100; https://github.com/torvalds/linux/blob/master/drivers/tty/tty_port.c#L69 With e.g. CONFIG_HZ = 250 (as this is the case for Ubuntu 18.04 linux-image-4.15.0-37-generic), the default setting for close_delay is thus 125. When ioctl(fd, TIOCGSERIAL, &s) is executed, the setting returned in user space is '12' (125/10). When ioctl(fd, TIOCSSERIAL, &s) is then executed with the same setting '12', the value is interpreted as '120' which is different from the current setting and a EPERM error may be raised by set_serial_info() if !CAP_SYS_ADMIN. https://github.com/torvalds/linux/blob/master/drivers/usb/class/cdc-acm.c#L… Fixes: ba2d8ce9db0a6 ("cdc-acm: implement TIOCSSERIAL to avoid blocking close(2)") Signed-off-by: Anthony Mallet <anthony.mallet(a)laas.fr> Cc: stable <stable(a)vger.kernel.org> Link: https://lore.kernel.org/r/20200312133101.7096-2-anthony.mallet@laas.fr Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index da619176deca..47f09a6ce7bd 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -907,6 +907,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) { struct acm *acm = tty->driver_data; unsigned int closing_wait, close_delay; + unsigned int old_closing_wait, old_close_delay; int retval = 0; close_delay = msecs_to_jiffies(ss->close_delay * 10); @@ -914,18 +915,24 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) ASYNC_CLOSING_WAIT_NONE : msecs_to_jiffies(ss->closing_wait * 10); + /* we must redo the rounding here, so that the values match */ + old_close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; + old_closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? + ASYNC_CLOSING_WAIT_NONE : + jiffies_to_msecs(acm->port.closing_wait) / 10; + mutex_lock(&acm->port.mutex); - if (!capable(CAP_SYS_ADMIN)) { - if ((close_delay != acm->port.close_delay) || - (closing_wait != acm->port.closing_wait)) + if ((ss->close_delay != old_close_delay) || + (ss->closing_wait != old_closing_wait)) { + if (!capable(CAP_SYS_ADMIN)) retval = -EPERM; - else - retval = -EOPNOTSUPP; - } else { - acm->port.close_delay = close_delay; - acm->port.closing_wait = closing_wait; - } + else { + acm->port.close_delay = close_delay; + acm->port.closing_wait = closing_wait; + } + } else + retval = -EOPNOTSUPP; mutex_unlock(&acm->port.mutex); return retval;

5 years, 7 months

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FAILED: patch "[PATCH] USB: cdc-acm: fix rounding error in TIOCSSERIAL" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b401f8c4f492cbf74f3f59c9141e5be3071071bb Mon Sep 17 00:00:00 2001 From: Anthony Mallet <anthony.mallet(a)laas.fr> Date: Thu, 12 Mar 2020 14:31:01 +0100 Subject: [PATCH] USB: cdc-acm: fix rounding error in TIOCSSERIAL By default, tty_port_init() initializes those parameters to a multiple of HZ. For instance in line 69 of tty_port.c: port->close_delay = (50 * HZ) / 100; https://github.com/torvalds/linux/blob/master/drivers/tty/tty_port.c#L69 With e.g. CONFIG_HZ = 250 (as this is the case for Ubuntu 18.04 linux-image-4.15.0-37-generic), the default setting for close_delay is thus 125. When ioctl(fd, TIOCGSERIAL, &s) is executed, the setting returned in user space is '12' (125/10). When ioctl(fd, TIOCSSERIAL, &s) is then executed with the same setting '12', the value is interpreted as '120' which is different from the current setting and a EPERM error may be raised by set_serial_info() if !CAP_SYS_ADMIN. https://github.com/torvalds/linux/blob/master/drivers/usb/class/cdc-acm.c#L… Fixes: ba2d8ce9db0a6 ("cdc-acm: implement TIOCSSERIAL to avoid blocking close(2)") Signed-off-by: Anthony Mallet <anthony.mallet(a)laas.fr> Cc: stable <stable(a)vger.kernel.org> Link: https://lore.kernel.org/r/20200312133101.7096-2-anthony.mallet@laas.fr Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index da619176deca..47f09a6ce7bd 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -907,6 +907,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) { struct acm *acm = tty->driver_data; unsigned int closing_wait, close_delay; + unsigned int old_closing_wait, old_close_delay; int retval = 0; close_delay = msecs_to_jiffies(ss->close_delay * 10); @@ -914,18 +915,24 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) ASYNC_CLOSING_WAIT_NONE : msecs_to_jiffies(ss->closing_wait * 10); + /* we must redo the rounding here, so that the values match */ + old_close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; + old_closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? + ASYNC_CLOSING_WAIT_NONE : + jiffies_to_msecs(acm->port.closing_wait) / 10; + mutex_lock(&acm->port.mutex); - if (!capable(CAP_SYS_ADMIN)) { - if ((close_delay != acm->port.close_delay) || - (closing_wait != acm->port.closing_wait)) + if ((ss->close_delay != old_close_delay) || + (ss->closing_wait != old_closing_wait)) { + if (!capable(CAP_SYS_ADMIN)) retval = -EPERM; - else - retval = -EOPNOTSUPP; - } else { - acm->port.close_delay = close_delay; - acm->port.closing_wait = closing_wait; - } + else { + acm->port.close_delay = close_delay; + acm->port.closing_wait = closing_wait; + } + } else + retval = -EOPNOTSUPP; mutex_unlock(&acm->port.mutex); return retval;

5 years, 7 months

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FAILED: patch "[PATCH] USB: cdc-acm: fix rounding error in TIOCSSERIAL" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b401f8c4f492cbf74f3f59c9141e5be3071071bb Mon Sep 17 00:00:00 2001 From: Anthony Mallet <anthony.mallet(a)laas.fr> Date: Thu, 12 Mar 2020 14:31:01 +0100 Subject: [PATCH] USB: cdc-acm: fix rounding error in TIOCSSERIAL By default, tty_port_init() initializes those parameters to a multiple of HZ. For instance in line 69 of tty_port.c: port->close_delay = (50 * HZ) / 100; https://github.com/torvalds/linux/blob/master/drivers/tty/tty_port.c#L69 With e.g. CONFIG_HZ = 250 (as this is the case for Ubuntu 18.04 linux-image-4.15.0-37-generic), the default setting for close_delay is thus 125. When ioctl(fd, TIOCGSERIAL, &s) is executed, the setting returned in user space is '12' (125/10). When ioctl(fd, TIOCSSERIAL, &s) is then executed with the same setting '12', the value is interpreted as '120' which is different from the current setting and a EPERM error may be raised by set_serial_info() if !CAP_SYS_ADMIN. https://github.com/torvalds/linux/blob/master/drivers/usb/class/cdc-acm.c#L… Fixes: ba2d8ce9db0a6 ("cdc-acm: implement TIOCSSERIAL to avoid blocking close(2)") Signed-off-by: Anthony Mallet <anthony.mallet(a)laas.fr> Cc: stable <stable(a)vger.kernel.org> Link: https://lore.kernel.org/r/20200312133101.7096-2-anthony.mallet@laas.fr Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index da619176deca..47f09a6ce7bd 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -907,6 +907,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) { struct acm *acm = tty->driver_data; unsigned int closing_wait, close_delay; + unsigned int old_closing_wait, old_close_delay; int retval = 0; close_delay = msecs_to_jiffies(ss->close_delay * 10); @@ -914,18 +915,24 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss) ASYNC_CLOSING_WAIT_NONE : msecs_to_jiffies(ss->closing_wait * 10); + /* we must redo the rounding here, so that the values match */ + old_close_delay = jiffies_to_msecs(acm->port.close_delay) / 10; + old_closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? + ASYNC_CLOSING_WAIT_NONE : + jiffies_to_msecs(acm->port.closing_wait) / 10; + mutex_lock(&acm->port.mutex); - if (!capable(CAP_SYS_ADMIN)) { - if ((close_delay != acm->port.close_delay) || - (closing_wait != acm->port.closing_wait)) + if ((ss->close_delay != old_close_delay) || + (ss->closing_wait != old_closing_wait)) { + if (!capable(CAP_SYS_ADMIN)) retval = -EPERM; - else - retval = -EOPNOTSUPP; - } else { - acm->port.close_delay = close_delay; - acm->port.closing_wait = closing_wait; - } + else { + acm->port.close_delay = close_delay; + acm->port.closing_wait = closing_wait; + } + } else + retval = -EOPNOTSUPP; mutex_unlock(&acm->port.mutex); return retval;

5 years, 7 months

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[PATCH v6 05/16] exec: Add exec_update_mutex to replace cred_guard_mutex

by Bernd Edlinger

The cred_guard_mutex is problematic as it is held over possibly indefinite waits for userspace. The possible indefinite waits for userspace that I have identified are: The cred_guard_mutex is held in PTRACE_EVENT_EXIT waiting for the tracer. The cred_guard_mutex is held over "put_user(0, tsk->clear_child_tid)" in exit_mm(). The cred_guard_mutex is held over "get_user(futex_offset, ...") in exit_robust_list. The cred_guard_mutex held over copy_strings. The functions get_user and put_user can trigger a page fault which can potentially wait indefinitely in the case of userfaultfd or if userspace implements part of the page fault path. In any of those cases the userspace process that the kernel is waiting for might make a different system call that winds up taking the cred_guard_mutex and result in deadlock. Holding a mutex over any of those possibly indefinite waits for userspace does not appear necessary. Add exec_update_mutex that will just cover updating the process during exec where the permissions and the objects pointed to by the task struct may be out of sync. The plan is to switch the users of cred_guard_mutex to exec_update_mutex one by one. This lets us move forward while still being careful and not introducing any regressions. Link: https://lore.kernel.org/lkml/20160921152946.GA24210@dhcp22.suse.cz/ Link: https://lore.kernel.org/lkml/AM6PR03MB5170B06F3A2B75EFB98D071AE4E60@AM6PR03… Link: https://lore.kernel.org/linux-fsdevel/20161102181806.GB1112@redhat.com/ Link: https://lore.kernel.org/lkml/20160923095031.GA14923@redhat.com/ Link: https://lore.kernel.org/lkml/20170213141452.GA30203@redhat.com/ Ref: 45c1a159b85b ("Add PTRACE_O_TRACEVFORKDONE and PTRACE_O_TRACEEXIT facilities.") Ref: 456f17cd1a28 ("[PATCH] user-vm-unlock-2.5.31-A2") Signed-off-by: "Eric W. Biederman" <ebiederm(a)xmission.com> Signed-off-by: Bernd Edlinger <bernd.edlinger(a)hotmail.de> --- fs/exec.c | 22 +++++++++++++++++++--- include/linux/binfmts.h | 8 +++++++- include/linux/sched/signal.h | 9 ++++++++- init/init_task.c | 1 + kernel/fork.c | 1 + 5 files changed, 36 insertions(+), 5 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index d820a72..0e46ec5 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1010,16 +1010,26 @@ ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len) } EXPORT_SYMBOL(read_code); +/* + * Maps the mm_struct mm into the current task struct. + * On success, this function returns with the mutex + * exec_update_mutex locked. + */ static int exec_mmap(struct mm_struct *mm) { struct task_struct *tsk; struct mm_struct *old_mm, *active_mm; + int ret; /* Notify parent that we're no longer interested in the old VM */ tsk = current; old_mm = current->mm; exec_mm_release(tsk, old_mm); + ret = mutex_lock_killable(&tsk->signal->exec_update_mutex); + if (ret) + return ret; + if (old_mm) { sync_mm_rss(old_mm); /* @@ -1031,9 +1041,11 @@ static int exec_mmap(struct mm_struct *mm) down_read(&old_mm->mmap_sem); if (unlikely(old_mm->core_state)) { up_read(&old_mm->mmap_sem); + mutex_unlock(&tsk->signal->exec_update_mutex); return -EINTR; } } + task_lock(tsk); active_mm = tsk->active_mm; membarrier_exec_mmap(mm); @@ -1288,11 +1300,12 @@ int flush_old_exec(struct linux_binprm * bprm) goto out; /* - * After clearing bprm->mm (to mark that current is using the - * prepared mm now), we have nothing left of the original + * After setting bprm->called_exec_mmap (to mark that current is + * using the prepared mm now), we have nothing left of the original * process. If anything from here on returns an error, the check * in search_binary_handler() will SEGV current. */ + bprm->called_exec_mmap = 1; bprm->mm = NULL; #ifdef CONFIG_POSIX_TIMERS @@ -1438,6 +1451,8 @@ static void free_bprm(struct linux_binprm *bprm) { free_arg_pages(bprm); if (bprm->cred) { + if (bprm->called_exec_mmap) + mutex_unlock(&current->signal->exec_update_mutex); mutex_unlock(&current->signal->cred_guard_mutex); abort_creds(bprm->cred); } @@ -1487,6 +1502,7 @@ void install_exec_creds(struct linux_binprm *bprm) * credentials; any time after this it may be unlocked. */ security_bprm_committed_creds(bprm); + mutex_unlock(&current->signal->exec_update_mutex); mutex_unlock(&current->signal->cred_guard_mutex); } EXPORT_SYMBOL(install_exec_creds); @@ -1678,7 +1694,7 @@ int search_binary_handler(struct linux_binprm *bprm) read_lock(&binfmt_lock); put_binfmt(fmt); - if (retval < 0 && !bprm->mm) { + if (retval < 0 && bprm->called_exec_mmap) { /* we got to flush_old_exec() and failed after it */ read_unlock(&binfmt_lock); force_sigsegv(SIGSEGV); diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index b40fc63..a345d9f 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -44,7 +44,13 @@ struct linux_binprm { * exec has happened. Used to sanitize execution environment * and to set AT_SECURE auxv for glibc. */ - secureexec:1; + secureexec:1, + /* + * Set by flush_old_exec, when exec_mmap has been called. + * This is past the point of no return, when the + * exec_update_mutex has been taken. + */ + called_exec_mmap:1; #ifdef __alpha__ unsigned int taso:1; #endif diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 8805025..a29df79 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -224,7 +224,14 @@ struct signal_struct { struct mutex cred_guard_mutex; /* guard against foreign influences on * credential calculations - * (notably. ptrace) */ + * (notably. ptrace) + * Deprecated do not use in new code. + * Use exec_update_mutex instead. + */ + struct mutex exec_update_mutex; /* Held while task_struct is being + * updated during exec, and may have + * inconsistent permissions. + */ } __randomize_layout; /* diff --git a/init/init_task.c b/init/init_task.c index 9e5cbe5..bd403ed 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -26,6 +26,7 @@ .multiprocess = HLIST_HEAD_INIT, .rlim = INIT_RLIMITS, .cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex), + .exec_update_mutex = __MUTEX_INITIALIZER(init_signals.exec_update_mutex), #ifdef CONFIG_POSIX_TIMERS .posix_timers = LIST_HEAD_INIT(init_signals.posix_timers), .cputimer = { diff --git a/kernel/fork.c b/kernel/fork.c index 8642530..036b692 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1594,6 +1594,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) sig->oom_score_adj_min = current->signal->oom_score_adj_min; mutex_init(&sig->cred_guard_mutex); + mutex_init(&sig->exec_update_mutex); return 0; } -- 1.9.1

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