- 03 Apr, 2019 40 commits
-
-
Filipe Manana authored
commit bf504110 upstream. If we do a shrinking truncate against an inode which is already present in the respective log tree and then rename it, as part of logging the new name we end up logging an inode item that reflects the old size of the file (the one which we previously logged) and not the new smaller size. The decision to preserve the size previously logged was added by commit 1a4bcf47 ("Btrfs: fix fsync data loss after adding hard link to inode") in order to avoid data loss after replaying the log. However that decision is only needed for the case the logged inode size is smaller then the current size of the inode, as explained in that commit's change log. If the current size of the inode is smaller then the previously logged size, we know a shrinking truncate happened and therefore need to use that smaller size. Example to trigger the problem: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0xab 0 8000" /mnt/foo $ xfs_io -c "fsync" /mnt/foo $ xfs_io -c "truncate 3000" /mnt/foo $ mv /mnt/foo /mnt/bar $ xfs_io -c "fsync" /mnt/bar <power failure> $ mount /dev/sdb /mnt $ od -t x1 -A d /mnt/bar 0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab * 0008000 Once we rename the file, we log its name (and inode item), and because the inode was already logged before in the current transaction, we log it with a size of 8000 bytes because that is the size we previously logged (with the first fsync). As part of the rename, besides logging the inode, we do also sync the log, which is done since commit d4682ba0 ("Btrfs: sync log after logging new name"), so the next fsync against our inode is effectively a no-op, since no new changes happened since the rename operation. Even if did not sync the log during the rename operation, the same problem (fize size of 8000 bytes instead of 3000 bytes) would be visible after replaying the log if the log ended up getting synced to disk through some other means, such as for example by fsyncing some other modified file. In the example above the fsync after the rename operation is there just because not every filesystem may guarantee logging/journalling the inode (and syncing the log/journal) during the rename operation, for example it is needed for f2fs, but not for ext4 and xfs. Fix this scenario by, when logging a new name (which is triggered by rename and link operations), using the current size of the inode instead of the previously logged inode size. A test case for fstests follows soon. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202695 CC: stable@vger.kernel.org # 4.4+ Reported-by: Seulbae Kim <seulbae@gatech.edu> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit 92edf8df upstream. When I updated the spectre_v2 reporting to handle software count cache flush I got the logic wrong when there's no software count cache enabled at all. The result is that on systems with the software count cache flush disabled we print: Mitigation: Indirect branch cache disabled, Software count cache flush Which correctly indicates that the count cache is disabled, but incorrectly says the software count cache flush is enabled. The root of the problem is that we are trying to handle all combinations of options. But we know now that we only expect to see the software count cache flush enabled if the other options are false. So split the two cases, which simplifies the logic and fixes the bug. We were also missing a space before "(hardware accelerated)". The result is we see one of: Mitigation: Indirect branch serialisation (kernel only) Mitigation: Indirect branch cache disabled Mitigation: Software count cache flush Mitigation: Software count cache flush (hardware accelerated) Fixes: ee13cb24 ("powerpc/64s: Add support for software count cache flush") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Christophe Leroy authored
commit 27da8071 upstream. The commit identified below adds MC_BTB_FLUSH macro only when CONFIG_PPC_FSL_BOOK3E is defined. This results in the following error on some configs (seen several times with kisskb randconfig_defconfig) arch/powerpc/kernel/exceptions-64e.S:576: Error: Unrecognized opcode: `mc_btb_flush' make[3]: *** [scripts/Makefile.build:367: arch/powerpc/kernel/exceptions-64e.o] Error 1 make[2]: *** [scripts/Makefile.build:492: arch/powerpc/kernel] Error 2 make[1]: *** [Makefile:1043: arch/powerpc] Error 2 make: *** [Makefile:152: sub-make] Error 2 This patch adds a blank definition of MC_BTB_FLUSH for other cases. Fixes: 10c5e83a ("powerpc/fsl: Flush the branch predictor at each kernel entry (64bit)") Cc: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 039daac5 upstream. Fixed the following build warning: powerpc-linux-gnu-ld: warning: orphan section `__btb_flush_fixup' from `arch/powerpc/kernel/head_44x.o' being placed in section `__btb_flush_fixup'. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit dfa88658 upstream. Report branch predictor state flush as a mitigation for Spectre variant 2. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 3bc8ea86 upstream. If the user choses not to use the mitigations, replace the code sequence with nops. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit e7aa61f4 upstream. Switching from the guest to host is another place where the speculative accesses can be exploited. Flush the branch predictor when entering KVM. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 7fef4362 upstream. In order to protect against speculation attacks on indirect branches, the branch predictor is flushed at kernel entry to protect for the following situations: - userspace process attacking another userspace process - userspace process attacking the kernel Basically when the privillege level change (i.e.the kernel is entered), the branch predictor state is flushed. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 10c5e83a upstream. In order to protect against speculation attacks on indirect branches, the branch predictor is flushed at kernel entry to protect for the following situations: - userspace process attacking another userspace process - userspace process attacking the kernel Basically when the privillege level change (i.e. the kernel is entered), the branch predictor state is flushed. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit f633a8ad upstream. When the command line argument is present, the Spectre variant 2 mitigations are disabled. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 98518c4d upstream. In order to flush the branch predictor the guest kernel performs writes to the BUCSR register which is hypervisor privilleged. However, the branch predictor is flushed at each KVM entry, so the branch predictor has been already flushed, so just return as soon as possible to guest. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Tweak comment formatting] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 7d8bad99 upstream. Currently for CONFIG_PPC_FSL_BOOK3E the spectre_v2 file is incorrect: $ cat /sys/devices/system/cpu/vulnerabilities/spectre_v2 "Mitigation: Software count cache flush" Which is wrong. Fix it to report vulnerable for now. Fixes: ee13cb24 ("powerpc/64s: Add support for software count cache flush") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 1cbf8990 upstream. The BUCSR register can be used to invalidate the entries in the branch prediction mechanisms. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 76a5eaa3 upstream. In order to protect against speculation attacks (Spectre variant 2) on NXP PowerPC platforms, the branch predictor should be flushed when the privillege level is changed. This patch is adding the infrastructure to fixup at runtime the code sections that are performing the branch predictor flush depending on a boot arg parameter which is added later in a separate patch. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit 99d54754 upstream. Look for fw-features properties to determine the appropriate settings for the count cache flush, and then call the generic powerpc code to set it up based on the security feature flags. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit ba72dc17 upstream. Use the existing hypercall to determine the appropriate settings for the count cache flush, and then call the generic powerpc code to set it up based on the security feature flags. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit ee13cb24 upstream. Some CPU revisions support a mode where the count cache needs to be flushed by software on context switch. Additionally some revisions may have a hardware accelerated flush, in which case the software flush sequence can be shortened. If we detect the appropriate flag from firmware we patch a branch into _switch() which takes us to a count cache flush sequence. That sequence in turn may be patched to return early if we detect that the CPU supports accelerating the flush sequence in hardware. Add debugfs support for reporting the state of the flush, as well as runtime disabling it. And modify the spectre_v2 sysfs file to report the state of the software flush. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit dc8c6cce upstream. Add security feature flags to indicate the need for software to flush the count cache on context switch, and for the presence of a hardware assisted count cache flush. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit 06d0bbc6 upstream. Add a macro and some helper C functions for patching single asm instructions. The gas macro means we can do something like: 1: nop patch_site 1b, patch__foo Which is less visually distracting than defining a GLOBAL symbol at 1, and also doesn't pollute the symbol table which can confuse eg. perf. These are obviously similar to our existing feature sections, but are not automatically patched based on CPU/MMU features, rather they are designed to be manually patched by C code at some arbitrary point. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit c28218d4 upstream. Used barrier_nospec to sanitize the syscall table. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit ebcd1bfc upstream. Implement the barrier_nospec as a isync;sync instruction sequence. The implementation uses the infrastructure built for BOOK3S 64. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 406d2b6a upstream. In a subsequent patch we will enable building security.c for Book3E. However the NXP platforms are not vulnerable to Meltdown, so make the Meltdown vulnerability reporting PPC_BOOK3S_64 specific. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit af375eef upstream. Currently we require platform code to call setup_barrier_nospec(). But if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case then we can call it in setup_arch(). Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit 179ab1cb upstream. Add a config symbol to encode which platforms support the barrier_nospec speculation barrier. Currently this is just Book3S 64 but we will add Book3E in a future patch. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit 6453b532 upstream. NXP Book3E platforms are not vulnerable to speculative store bypass, so make the mitigations PPC_BOOK3S_64 specific. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diana Craciun authored
commit cf175dc3 upstream. The speculation barrier can be disabled from the command line with the parameter: "nospectre_v1". Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit 6d44acae upstream. When I added the spectre_v2 information in sysfs, I included the availability of the ori31 speculation barrier. Although the ori31 barrier can be used to mitigate v2, it's primarily intended as a spectre v1 mitigation. Spectre v2 is mitigated by hardware changes. So rework the sysfs files to show the ori31 information in the spectre_v1 file, rather than v2. Currently we display eg: $ grep . spectre_v* spectre_v1:Mitigation: __user pointer sanitization spectre_v2:Mitigation: Indirect branch cache disabled, ori31 speculation barrier enabled After: $ grep . spectre_v* spectre_v1:Mitigation: __user pointer sanitization, ori31 speculation barrier enabled spectre_v2:Mitigation: Indirect branch cache disabled Fixes: d6fbe1c5 ("powerpc/64s: Wire up cpu_show_spectre_v2()") Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michal Suchanek authored
commit a3775145 upstream. We now have barrier_nospec as mitigation so print it in cpu_show_spectre_v1() when enabled. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit 51973a81 upstream. Our syscall entry is done in assembly so patch in an explicit barrier_nospec. Based on a patch by Michal Suchanek. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Ellerman authored
commit ddf35cf3 upstream. Based on the x86 commit doing the same. See commit 304ec1b0 ("x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec") and b3bbfb3f ("x86: Introduce __uaccess_begin_nospec() and uaccess_try_nospec") for more detail. In all cases we are ordering the load from the potentially user-controlled pointer vs a previous branch based on an access_ok() check or similar. Base on a patch from Michal Suchanek. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michal Suchanek authored
commit cb3d6759 upstream. Check what firmware told us and enable/disable the barrier_nospec as appropriate. We err on the side of enabling the barrier, as it's no-op on older systems, see the comment for more detail. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michal Suchanek authored
commit 815069ca upstream. Note that unlike RFI which is patched only in kernel the nospec state reflects settings at the time the module was loaded. Iterating all modules and re-patching every time the settings change is not implemented. Based on lwsync patching. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michal Suchanek authored
commit 2eea7f06 upstream. Based on the RFI patching. This is required to be able to disable the speculation barrier. Only one barrier type is supported and it does nothing when the firmware does not enable it. Also re-patching modules is not supported So the only meaningful thing that can be done is patching out the speculation barrier at boot when the user says it is not wanted. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Eric Dumazet authored
commit 9180bb4f upstream. In my latest patch I missed one rcu_read_unlock(), in case device is down. Fixes: 4477138f ("tun: properly test for IFF_UP") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Eric Dumazet authored
[ Upstream commit 4477138f ] Same reasons than the ones explained in commit 4179cb5a ("vxlan: test dev->flags & IFF_UP before calling netif_rx()") netif_rx_ni() or napi_gro_frags() must be called under a strict contract. At device dismantle phase, core networking clears IFF_UP and flush_all_backlogs() is called after rcu grace period to make sure no incoming packet might be in a cpu backlog and still referencing the device. A similar protocol is used for gro layer. Most drivers call netif_rx() from their interrupt handler, and since the interrupts are disabled at device dismantle, netif_rx() does not have to check dev->flags & IFF_UP Virtual drivers do not have this guarantee, and must therefore make the check themselves. Fixes: 1bd4978a ("tun: honor IFF_UP in tun_get_user()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Finn Thain authored
[ Upstream commit bb9e5c5b ] The bug that Stan reported is as follows. After a restart, a 16-bit NIC may be incorrectly identified as a 32-bit NIC and stop working. mac8390 slot.E: Memory length resource not found, probing mac8390 slot.E: Farallon EtherMac II-C (type farallon) mac8390 slot.E: MAC 00:00:c5:30:c2:99, IRQ 61, 32 KB shared memory at 0xfeed0000, 32-bit access. The bug never arises after a cold start and only intermittently after a warm start. (I didn't investigate why the bug is intermittent.) It turns out that memcpy_toio() is deprecated and memcmp_withio() also has issues. Replacing these calls with mmio accessors fixes the problem. Reported-and-tested-by: Stan Johnson <userm57@yahoo.com> Fixes: 2964db0f ("m68k: Mac DP8390 update") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Dmitry Bogdanov authored
[ Upstream commit a7faaa0c ] TCP/UDP checksum validity was propagated to skb only if IP checksum is valid. But for IPv6 there is no validity as there is no checksum in IPv6. This patch propagates TCP/UDP checksum validity regardless of IP checksum. Fixes: 018423e9 ("net: ethernet: aquantia: Add ring support code") Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com> Signed-off-by: Nikita Danilov <nikita.danilov@aquantia.com> Signed-off-by: Dmitry Bogdanov <dmitry.bogdanov@aquantia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Xin Long authored
[ Upstream commit 273160ff ] sctp_hdr(skb) only works when skb->transport_header is set properly. But in Netfilter, skb->transport_header for ipv6 is not guaranteed to be right value for sctphdr. It would cause to fail to check the checksum for sctp packets. So fix it by using offset, which is always right in all places. v1->v2: - Fix the changelog. Fixes: e6d8b64b ("net: sctp: fix and consolidate SCTP checksumming code") Reported-by: Li Shuang <shuali@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Zhiqiang Liu authored
[ Upstream commit cc4807bb ] Commit ad6c9986 ("vxlan: Fix GRO cells race condition between receive and link delete") fixed a race condition for the typical case a vxlan device is dismantled from the current netns. But if a netns is dismantled, vxlan_destroy_tunnels() is called to schedule a unregister_netdevice_queue() of all the vxlan tunnels that are related to this netns. In vxlan_destroy_tunnels(), gro_cells_destroy() is called and finished before unregister_netdevice_queue(). This means that the gro_cells_destroy() call is done too soon, for the same reasons explained in above commit. So we need to fully respect the RCU rules, and thus must remove the gro_cells_destroy() call or risk use after-free. Fixes: 58ce31cc ("vxlan: GRO support at tunnel layer") Signed-off-by: Suanming.Mou <mousuanming@huawei.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Dean Nelson authored
[ Upstream commit cd35ef91 ] For the non-XDP case, commit 77322538 ("net: thunderx: Optimize page recycling for XDP") added code to nicvf_free_rbdr() that, when releasing the additional receive buffer page reference held for recycling, repeatedly calls put_page() until the page's _refcount goes to zero. Which results in the page being freed. This is not okay if the page's _refcount was greater than 1 (in the non-XDP case), because nicvf_free_rbdr() should not be subtracting more than what nicvf_alloc_page() had previously added to the page's _refcount, which was only 1 (in the non-XDP case). This can arise if a received packet is still being processed and the receive buffer (i.e., skb->head) has not yet been freed via skb_free_head() when nicvf_free_rbdr() is spinning through the aforementioned put_page() loop. If this should occur, when the received packet finishes processing and skb_free_head() is called, various problems can ensue. Exactly what, depends on whether the page has already been reallocated or not, anything from "BUG: Bad page state ... ", to "Unable to handle kernel NULL pointer dereference ..." or "Unable to handle kernel paging request...". So this patch changes nicvf_free_rbdr() to only call put_page() once for pages held for recycling (in the non-XDP case). Fixes: 77322538 ("net: thunderx: Optimize page recycling for XDP") Signed-off-by: Dean Nelson <dnelson@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-