linux-stable.git, branch v4.9.151 Linux kernel stable tree Linux 4.9.151 2019-01-16T21:12:33+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2019-01-16T21:12:33+00:00 008bfb9312968bc6af54e47746a9d9f66c8388c0 






sunrpc: use-after-free in svc_process_common()
2019-01-16T21:12:33+00:00

Vasily Averin
vvs@virtuozzo.com

2018-12-24T11:44:52+00:00

37c791a031ece3afeb9c8b023397473a5349f171

commit d4b09acf924b84bae77cad090a9d108e70b43643 upstream.

if node have NFSv41+ mounts inside several net namespaces
it can lead to use-after-free in svc_process_common()

svc_process_common()
        /* Setup reply header */
        rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp); <<< HERE

svc_process_common() can use incorrect rqstp->rq_xprt,
its caller function bc_svc_process() takes it from serv->sv_bc_xprt.
The problem is that serv is global structure but sv_bc_xprt
is assigned per-netnamespace.

According to Trond, the whole "let's set up rqstp->rq_xprt
for the back channel" is nothing but a giant hack in order
to work around the fact that svc_process_common() uses it
to find the xpt_ops, and perform a couple of (meaningless
for the back channel) tests of xpt_flags.

All we really need in svc_process_common() is to be able to run
rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr()

Bruce J Fields points that this xpo_prep_reply_hdr() call
is an awfully roundabout way just to do "svc_putnl(resv, 0);"
in the tcp case.

This patch does not initialiuze rqstp->rq_xprt in bc_svc_process(),
now it calls svc_process_common() with rqstp->rq_xprt = NULL.

To adjust reply header svc_process_common() just check
rqstp->rq_prot and calls svc_tcp_prep_reply_hdr() for tcp case.

To handle rqstp->rq_xprt = NULL case in functions called from
svc_process_common() patch intruduces net namespace pointer
svc_rqst->rq_bc_net and adjust SVC_NET() definition.
Some other function was also adopted to properly handle described case.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Cc: stable@vger.kernel.org
Fixes: 23c20ecd4475 ("NFS: callback up - users counting cleanup")
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
v2: - added lost extern svc_tcp_prep_reply_hdr()
    - dropped trace_svc_process() changes
    - context fixes in svc_process_common()
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>





commit d4b09acf924b84bae77cad090a9d108e70b43643 upstream.

if node have NFSv41+ mounts inside several net namespaces
it can lead to use-after-free in svc_process_common()

svc_process_common()
        /* Setup reply header */
        rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp); <<< HERE

svc_process_common() can use incorrect rqstp->rq_xprt,
its caller function bc_svc_process() takes it from serv->sv_bc_xprt.
The problem is that serv is global structure but sv_bc_xprt
is assigned per-netnamespace.

According to Trond, the whole "let's set up rqstp->rq_xprt
for the back channel" is nothing but a giant hack in order
to work around the fact that svc_process_common() uses it
to find the xpt_ops, and perform a couple of (meaningless
for the back channel) tests of xpt_flags.

All we really need in svc_process_common() is to be able to run
rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr()

Bruce J Fields points that this xpo_prep_reply_hdr() call
is an awfully roundabout way just to do "svc_putnl(resv, 0);"
in the tcp case.

This patch does not initialiuze rqstp->rq_xprt in bc_svc_process(),
now it calls svc_process_common() with rqstp->rq_xprt = NULL.

To adjust reply header svc_process_common() just check
rqstp->rq_prot and calls svc_tcp_prep_reply_hdr() for tcp case.

To handle rqstp->rq_xprt = NULL case in functions called from
svc_process_common() patch intruduces net namespace pointer
svc_rqst->rq_bc_net and adjust SVC_NET() definition.
Some other function was also adopted to properly handle described case.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Cc: stable@vger.kernel.org
Fixes: 23c20ecd4475 ("NFS: callback up - users counting cleanup")
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
v2: - added lost extern svc_tcp_prep_reply_hdr()
    - dropped trace_svc_process() changes
    - context fixes in svc_process_common()
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>







ext4: avoid kernel warning when writing the superblock to a dead device
2019-01-16T21:12:33+00:00

Theodore Ts'o
tytso@mit.edu

2018-12-31T04:20:39+00:00

c173c38416335aa8d82ae1dc2454672f3551d875

commit e86807862e6880809f191c4cea7f88a489f0ed34 upstream.

The xfstests generic/475 test switches the underlying device with
dm-error while running a stress test.  This results in a large number
of file system errors, and since we can't lock the buffer head when
marking the superblock dirty in the ext4_grp_locked_error() case, it's
possible the superblock to be !buffer_uptodate() without
buffer_write_io_error() being true.

We need to set buffer_uptodate() before we call mark_buffer_dirty() or
this will trigger a WARN_ON.  It's safe to do this since the
superblock must have been properly read into memory or the mount would
have been successful.  So if buffer_uptodate() is not set, we can
safely assume that this happened due to a failed attempt to write the
superblock.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit e86807862e6880809f191c4cea7f88a489f0ed34 upstream.

The xfstests generic/475 test switches the underlying device with
dm-error while running a stress test.  This results in a large number
of file system errors, and since we can't lock the buffer head when
marking the superblock dirty in the ext4_grp_locked_error() case, it's
possible the superblock to be !buffer_uptodate() without
buffer_write_io_error() being true.

We need to set buffer_uptodate() before we call mark_buffer_dirty() or
this will trigger a WARN_ON.  It's safe to do this since the
superblock must have been properly read into memory or the mount would
have been successful.  So if buffer_uptodate() is not set, we can
safely assume that this happened due to a failed attempt to write the
superblock.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








ext4: fix a potential fiemap/page fault deadlock w/ inline_data
2019-01-16T21:12:32+00:00

Theodore Ts'o
tytso@mit.edu

2018-12-25T05:56:33+00:00

eb24a3b6bb4f11e7dec1000cb3c08d6371d23181

commit 2b08b1f12cd664dc7d5c84ead9ff25ae97ad5491 upstream.

The ext4_inline_data_fiemap() function calls fiemap_fill_next_extent()
while still holding the xattr semaphore.  This is not necessary and it
triggers a circular lockdep warning.  This is because
fiemap_fill_next_extent() could trigger a page fault when it writes
into page which triggers a page fault.  If that page is mmaped from
the inline file in question, this could very well result in a
deadlock.

This problem can be reproduced using generic/519 with a file system
configuration which has the inline_data feature enabled.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 2b08b1f12cd664dc7d5c84ead9ff25ae97ad5491 upstream.

The ext4_inline_data_fiemap() function calls fiemap_fill_next_extent()
while still holding the xattr semaphore.  This is not necessary and it
triggers a circular lockdep warning.  This is because
fiemap_fill_next_extent() could trigger a page fault when it writes
into page which triggers a page fault.  If that page is mmaped from
the inline file in question, this could very well result in a
deadlock.

This problem can be reproduced using generic/519 with a file system
configuration which has the inline_data feature enabled.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








ext4: make sure enough credits are reserved for dioread_nolock writes
2019-01-16T21:12:32+00:00

Theodore Ts'o
tytso@mit.edu

2018-12-25T01:27:08+00:00

d1cfd9cba0cbc6638137b577ee09ee334701c827

commit 812c0cab2c0dfad977605dbadf9148490ca5d93f upstream.

There are enough credits reserved for most dioread_nolock writes;
however, if the extent tree is sufficiently deep, and/or quota is
enabled, the code was not allowing for all eventualities when
reserving journal credits for the unwritten extent conversion.

This problem can be seen using xfstests ext4/034:

   WARNING: CPU: 1 PID: 257 at fs/ext4/ext4_jbd2.c:271 __ext4_handle_dirty_metadata+0x10c/0x180
   Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
   RIP: 0010:__ext4_handle_dirty_metadata+0x10c/0x180
   	...
   EXT4-fs: ext4_free_blocks:4938: aborting transaction: error 28 in __ext4_handle_dirty_metadata
   EXT4: jbd2_journal_dirty_metadata failed: handle type 11 started at line 4921, credits 4/0, errcode -28
   EXT4-fs error (device dm-1) in ext4_free_blocks:4950: error 28

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 812c0cab2c0dfad977605dbadf9148490ca5d93f upstream.

There are enough credits reserved for most dioread_nolock writes;
however, if the extent tree is sufficiently deep, and/or quota is
enabled, the code was not allowing for all eventualities when
reserving journal credits for the unwritten extent conversion.

This problem can be seen using xfstests ext4/034:

   WARNING: CPU: 1 PID: 257 at fs/ext4/ext4_jbd2.c:271 __ext4_handle_dirty_metadata+0x10c/0x180
   Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
   RIP: 0010:__ext4_handle_dirty_metadata+0x10c/0x180
   	...
   EXT4-fs: ext4_free_blocks:4938: aborting transaction: error 28 in __ext4_handle_dirty_metadata
   EXT4: jbd2_journal_dirty_metadata failed: handle type 11 started at line 4921, credits 4/0, errcode -28
   EXT4-fs error (device dm-1) in ext4_free_blocks:4950: error 28

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








rbd: don't return 0 on unmap if RBD_DEV_FLAG_REMOVING is set
2019-01-16T21:12:32+00:00

Ilya Dryomov
idryomov@gmail.com

2019-01-08T18:47:38+00:00

f710ce8ad2f8e4167769b595f60b6ec92f6d7029

commit 85f5a4d666fd9be73856ed16bb36c5af5b406b29 upstream.

There is a window between when RBD_DEV_FLAG_REMOVING is set and when
the device is removed from rbd_dev_list.  During this window, we set
"already" and return 0.

Returning 0 from write(2) can confuse userspace tools because
0 indicates that nothing was written.  In particular, "rbd unmap"
will retry the write multiple times a second:

  10:28:05.463299 write(4, "0", 1)        = 0
  10:28:05.463509 write(4, "0", 1)        = 0
  10:28:05.463720 write(4, "0", 1)        = 0
  10:28:05.463942 write(4, "0", 1)        = 0
  10:28:05.464155 write(4, "0", 1)        = 0

Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 85f5a4d666fd9be73856ed16bb36c5af5b406b29 upstream.

There is a window between when RBD_DEV_FLAG_REMOVING is set and when
the device is removed from rbd_dev_list.  During this window, we set
"already" and return 0.

Returning 0 from write(2) can confuse userspace tools because
0 indicates that nothing was written.  In particular, "rbd unmap"
will retry the write multiple times a second:

  10:28:05.463299 write(4, "0", 1)        = 0
  10:28:05.463509 write(4, "0", 1)        = 0
  10:28:05.463720 write(4, "0", 1)        = 0
  10:28:05.463942 write(4, "0", 1)        = 0
  10:28:05.464155 write(4, "0", 1)        = 0

Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








i2c: dev: prevent adapter retries and timeout being set as minus value
2019-01-16T21:12:32+00:00

Yi Zeng
yizeng@asrmicro.com

2019-01-09T07:33:07+00:00

57cd3fad7644a22f7b0fab8e3e5670c3424852fb

commit 6ebec961d59bccf65d08b13fc1ad4e6272a89338 upstream.

If adapter->retries is set to a minus value from user space via ioctl,
it will make __i2c_transfer and __i2c_smbus_xfer skip the calling to
adapter->algo->master_xfer and adapter->algo->smbus_xfer that is
registered by the underlying bus drivers, and return value 0 to all the
callers. The bus driver will never be accessed anymore by all users,
besides, the users may still get successful return value without any
error or information log print out.

If adapter->timeout is set to minus value from user space via ioctl,
it will make the retrying loop in __i2c_transfer and __i2c_smbus_xfer
always break after the the first try, due to the time_after always
returns true.

Signed-off-by: Yi Zeng <yizeng@asrmicro.com>
[wsa: minor grammar updates to commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 6ebec961d59bccf65d08b13fc1ad4e6272a89338 upstream.

If adapter->retries is set to a minus value from user space via ioctl,
it will make __i2c_transfer and __i2c_smbus_xfer skip the calling to
adapter->algo->master_xfer and adapter->algo->smbus_xfer that is
registered by the underlying bus drivers, and return value 0 to all the
callers. The bus driver will never be accessed anymore by all users,
besides, the users may still get successful return value without any
error or information log print out.

If adapter->timeout is set to minus value from user space via ioctl,
it will make the retrying loop in __i2c_transfer and __i2c_smbus_xfer
always break after the the first try, due to the time_after always
returns true.

Signed-off-by: Yi Zeng <yizeng@asrmicro.com>
[wsa: minor grammar updates to commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








ACPI: power: Skip duplicate power resource references in _PRx
2019-01-16T21:12:32+00:00

Hans de Goede
hdegoede@redhat.com

2018-12-30T17:25:00+00:00

dff14f70dc0625eddb2dc76ff71e9044548a0457

commit 7d7b467cb95bf29597b417d4990160d4ea6d69b9 upstream.

Some ACPI tables contain duplicate power resource references like this:

        Name (_PR0, Package (0x04)  // _PR0: Power Resources for D0
        {
            P28P,
            P18P,
            P18P,
            CLK4
        })

This causes a WARN_ON in sysfs_add_link_to_group() because we end up
adding a link to the same acpi_device twice:

sysfs: cannot create duplicate filename '/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/808622C1:00/OVTI2680:00/power_resources_D0/LNXPOWER:0a'
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.12-301.fc29.x86_64 #1
Hardware name: Insyde CherryTrail/Type2 - Board Product Name, BIOS jumperx.T87.KFBNEEA02 04/13/2016
Call Trace:
 dump_stack+0x5c/0x80
 sysfs_warn_dup.cold.3+0x17/0x2a
 sysfs_do_create_link_sd.isra.2+0xa9/0xb0
 sysfs_add_link_to_group+0x30/0x50
 acpi_power_expose_list+0x74/0xa0
 acpi_power_add_remove_device+0x50/0xa0
 acpi_add_single_object+0x26b/0x5f0
 acpi_bus_check_add+0xc4/0x250
 ...

To address this issue, make acpi_extract_power_resources() check for
duplicates and simply skip them when found.

Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[ rjw: Subject & changelog, comments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 7d7b467cb95bf29597b417d4990160d4ea6d69b9 upstream.

Some ACPI tables contain duplicate power resource references like this:

        Name (_PR0, Package (0x04)  // _PR0: Power Resources for D0
        {
            P28P,
            P18P,
            P18P,
            CLK4
        })

This causes a WARN_ON in sysfs_add_link_to_group() because we end up
adding a link to the same acpi_device twice:

sysfs: cannot create duplicate filename '/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/808622C1:00/OVTI2680:00/power_resources_D0/LNXPOWER:0a'
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.12-301.fc29.x86_64 #1
Hardware name: Insyde CherryTrail/Type2 - Board Product Name, BIOS jumperx.T87.KFBNEEA02 04/13/2016
Call Trace:
 dump_stack+0x5c/0x80
 sysfs_warn_dup.cold.3+0x17/0x2a
 sysfs_do_create_link_sd.isra.2+0xa9/0xb0
 sysfs_add_link_to_group+0x30/0x50
 acpi_power_expose_list+0x74/0xa0
 acpi_power_add_remove_device+0x50/0xa0
 acpi_add_single_object+0x26b/0x5f0
 acpi_bus_check_add+0xc4/0x250
 ...

To address this issue, make acpi_extract_power_resources() check for
duplicates and simply skip them when found.

Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[ rjw: Subject & changelog, comments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








mm: page_mapped: don't assume compound page is huge or THP
2019-01-16T21:12:32+00:00

Jan Stancek
jstancek@redhat.com

2019-01-08T23:23:28+00:00

be22579ac9fde58215cfe72f72d4a01f8e4d1423

commit 8ab88c7169b7fba98812ead6524b9d05bc76cf00 upstream.

LTP proc01 testcase has been observed to rarely trigger crashes
on arm64:
    page_mapped+0x78/0xb4
    stable_page_flags+0x27c/0x338
    kpageflags_read+0xfc/0x164
    proc_reg_read+0x7c/0xb8
    __vfs_read+0x58/0x178
    vfs_read+0x90/0x14c
    SyS_read+0x60/0xc0

The issue is that page_mapped() assumes that if compound page is not
huge, then it must be THP.  But if this is 'normal' compound page
(COMPOUND_PAGE_DTOR), then following loop can keep running (for
HPAGE_PMD_NR iterations) until it tries to read from memory that isn't
mapped and triggers a panic:

        for (i = 0; i < hpage_nr_pages(page); i++) {
                if (atomic_read(&page[i]._mapcount) >= 0)
                        return true;
	}

I could replicate this on x86 (v4.20-rc4-98-g60b548237fed) only
with a custom kernel module [1] which:
 - allocates compound page (PAGEC) of order 1
 - allocates 2 normal pages (COPY), which are initialized to 0xff (to
   satisfy _mapcount >= 0)
 - 2 PAGEC page structs are copied to address of first COPY page
 - second page of COPY is marked as not present
 - call to page_mapped(COPY) now triggers fault on access to 2nd COPY
   page at offset 0x30 (_mapcount)

[1] https://github.com/jstancek/reproducers/blob/master/kernel/page_mapped_crash/repro.c

Fix the loop to iterate for "1 << compound_order" pages.

Kirrill said "IIRC, sound subsystem can producuce custom mapped compound
pages".

Link: http://lkml.kernel.org/r/c440d69879e34209feba21e12d236d06bc0a25db.1543577156.git.jstancek@redhat.com
Fixes: e1534ae95004 ("mm: differentiate page_mapped() from page_mapcount() for compound pages")
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Debugged-by: Laszlo Ersek <lersek@redhat.com>
Suggested-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 8ab88c7169b7fba98812ead6524b9d05bc76cf00 upstream.

LTP proc01 testcase has been observed to rarely trigger crashes
on arm64:
    page_mapped+0x78/0xb4
    stable_page_flags+0x27c/0x338
    kpageflags_read+0xfc/0x164
    proc_reg_read+0x7c/0xb8
    __vfs_read+0x58/0x178
    vfs_read+0x90/0x14c
    SyS_read+0x60/0xc0

The issue is that page_mapped() assumes that if compound page is not
huge, then it must be THP.  But if this is 'normal' compound page
(COMPOUND_PAGE_DTOR), then following loop can keep running (for
HPAGE_PMD_NR iterations) until it tries to read from memory that isn't
mapped and triggers a panic:

        for (i = 0; i < hpage_nr_pages(page); i++) {
                if (atomic_read(&page[i]._mapcount) >= 0)
                        return true;
	}

I could replicate this on x86 (v4.20-rc4-98-g60b548237fed) only
with a custom kernel module [1] which:
 - allocates compound page (PAGEC) of order 1
 - allocates 2 normal pages (COPY), which are initialized to 0xff (to
   satisfy _mapcount >= 0)
 - 2 PAGEC page structs are copied to address of first COPY page
 - second page of COPY is marked as not present
 - call to page_mapped(COPY) now triggers fault on access to 2nd COPY
   page at offset 0x30 (_mapcount)

[1] https://github.com/jstancek/reproducers/blob/master/kernel/page_mapped_crash/repro.c

Fix the loop to iterate for "1 << compound_order" pages.

Kirrill said "IIRC, sound subsystem can producuce custom mapped compound
pages".

Link: http://lkml.kernel.org/r/c440d69879e34209feba21e12d236d06bc0a25db.1543577156.git.jstancek@redhat.com
Fixes: e1534ae95004 ("mm: differentiate page_mapped() from page_mapcount() for compound pages")
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Debugged-by: Laszlo Ersek <lersek@redhat.com>
Suggested-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








slab: alien caches must not be initialized if the allocation of the alien cache failed
2019-01-16T21:12:32+00:00

Christoph Lameter
cl@linux.com

2019-01-08T23:23:00+00:00

cab42485971c38b1b1739918f526bb5935980abc

commit 09c2e76ed734a1d36470d257a778aaba28e86531 upstream.

Callers of __alloc_alien() check for NULL.  We must do the same check in
__alloc_alien_cache to avoid NULL pointer dereferences on allocation
failures.

Link: http://lkml.kernel.org/r/010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@email.amazonses.com
Fixes: 49dfc304ba241 ("slab: use the lock on alien_cache, instead of the lock on array_cache")
Fixes: c8522a3a5832b ("Slab: introduce alloc_alien")
Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-by: syzbot+d6ed4ec679652b4fd4e4@syzkaller.appspotmail.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 09c2e76ed734a1d36470d257a778aaba28e86531 upstream.

Callers of __alloc_alien() check for NULL.  We must do the same check in
__alloc_alien_cache to avoid NULL pointer dereferences on allocation
failures.

Link: http://lkml.kernel.org/r/010001680f42f192-82b4e12e-1565-4ee0-ae1f-1e98974906aa-000000@email.amazonses.com
Fixes: 49dfc304ba241 ("slab: use the lock on alien_cache, instead of the lock on array_cache")
Fixes: c8522a3a5832b ("Slab: introduce alloc_alien")
Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-by: syzbot+d6ed4ec679652b4fd4e4@syzkaller.appspotmail.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>