kernel/linux.git/lib, branch v4.14.284

nodemask: Fix return values to be unsigned

2022-06-14T14:54:01+00:00

[ Upstream commit 0dfe54071d7c828a02917b595456bfde1afdddc9 ] The nodemask routines had mixed return values that provided potentially signed return values that could never happen. This was leading to the compiler getting confusing about the range of possible return values (it was thinking things could be negative where they could not be). Fix all the nodemask routines that should be returning unsigned (or bool) values. Silences: mm/swapfile.c: In function ‘setup_swap_info’: mm/swapfile.c:2291:47: error: array subscript -1 is below array bounds of ‘struct plist_node[]’ [-Werror=array-bounds] 2291 | p->avail_lists[i].prio = 1; | ~~~~~~~~~~~~~~^~~ In file included from mm/swapfile.c:16: ./include/linux/swap.h:292:27: note: while referencing ‘avail_lists’ 292 | struct plist_node avail_lists[]; /* | ^~~~~~~~~~~ Reported-by: Christophe de Dinechin Link: https://lore.kernel.org/lkml/20220414150855.2407137-3-dinechin@redhat.com/ Cc: Alexey Dobriyan Cc: Yury Norov Cc: Andy Shevchenko Cc: Rasmus Villemoes Cc: Andrew Morton Cc: Zhen Lei Signed-off-by: Kees Cook Signed-off-by: Yury Norov Signed-off-by: Sasha Levin

dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC

2022-06-14T14:53:45+00:00

[ Upstream commit 84bc4f1dbbbb5f8aa68706a96711dccb28b518e5 ] We observed the error "cacheline tracking ENOMEM, dma-debug disabled" during a light system load (copying some files). The reason for this error is that the dma_active_cacheline radix tree uses GFP_NOWAIT allocation - so it can't access the emergency memory reserves and it fails as soon as anybody reaches the watermark. This patch changes GFP_NOWAIT to GFP_ATOMIC, so that it can access the emergency memory reserves. Signed-off-by: Mikulas Patocka Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin

assoc_array: Fix BUG_ON during garbage collect

2022-06-06T06:20:56+00:00

commit d1dc87763f406d4e67caf16dbe438a5647692395 upstream. A rare BUG_ON triggered in assoc_array_gc: [3430308.818153] kernel BUG at lib/assoc_array.c:1609! Which corresponded to the statement currently at line 1593 upstream: BUG_ON(assoc_array_ptr_is_meta(p)); Using the data from the core dump, I was able to generate a userspace reproducer[1] and determine the cause of the bug. [1]: https://github.com/brenns10/kernel_stuff/tree/master/assoc_array_gc After running the iterator on the entire branch, an internal tree node looked like the following: NODE (nr_leaves_on_branch: 3) SLOT [0] NODE (2 leaves) SLOT [1] NODE (1 leaf) SLOT [2..f] NODE (empty) In the userspace reproducer, the pr_devel output when compressing this node was: -- compress node 0x5607cc089380 -- free=0, leaves=0 [0] retain node 2/1 [nx 0] [1] fold node 1/1 [nx 0] [2] fold node 0/1 [nx 2] [3] fold node 0/2 [nx 2] [4] fold node 0/3 [nx 2] [5] fold node 0/4 [nx 2] [6] fold node 0/5 [nx 2] [7] fold node 0/6 [nx 2] [8] fold node 0/7 [nx 2] [9] fold node 0/8 [nx 2] [10] fold node 0/9 [nx 2] [11] fold node 0/10 [nx 2] [12] fold node 0/11 [nx 2] [13] fold node 0/12 [nx 2] [14] fold node 0/13 [nx 2] [15] fold node 0/14 [nx 2] after: 3 At slot 0, an internal node with 2 leaves could not be folded into the node, because there was only one available slot (slot 0). Thus, the internal node was retained. At slot 1, the node had one leaf, and was able to be folded in successfully. The remaining nodes had no leaves, and so were removed. By the end of the compression stage, there were 14 free slots, and only 3 leaf nodes. The tree was ascended and then its parent node was compressed. When this node was seen, it could not be folded, due to the internal node it contained. The invariant for compression in this function is: whenever nr_leaves_on_branch < ASSOC_ARRAY_FAN_OUT, the node should contain all leaf nodes. The compression step currently cannot guarantee this, given the corner case shown above. To fix this issue, retry compression whenever we have retained a node, and yet nr_leaves_on_branch < ASSOC_ARRAY_FAN_OUT. This second compression will then allow the node in slot 1 to be folded in, satisfying the invariant. Below is the output of the reproducer once the fix is applied: -- compress node 0x560e9c562380 -- free=0, leaves=0 [0] retain node 2/1 [nx 0] [1] fold node 1/1 [nx 0] [2] fold node 0/1 [nx 2] [3] fold node 0/2 [nx 2] [4] fold node 0/3 [nx 2] [5] fold node 0/4 [nx 2] [6] fold node 0/5 [nx 2] [7] fold node 0/6 [nx 2] [8] fold node 0/7 [nx 2] [9] fold node 0/8 [nx 2] [10] fold node 0/9 [nx 2] [11] fold node 0/10 [nx 2] [12] fold node 0/11 [nx 2] [13] fold node 0/12 [nx 2] [14] fold node 0/13 [nx 2] [15] fold node 0/14 [nx 2] internal nodes remain despite enough space, retrying -- compress node 0x560e9c562380 -- free=14, leaves=1 [0] fold node 2/15 [nx 0] after: 3 Changes ======= DH: - Use false instead of 0. - Reorder the inserted lines in a couple of places to put retained before next_slot. ver #2) - Fix typo in pr_devel, correct comparison to "<=" Fixes: 3cb989501c26 ("Add a generic associative array implementation.") Cc: Signed-off-by: Stephen Brennan Signed-off-by: David Howells cc: Andrew Morton cc: keyrings@vger.kernel.org Link: https://lore.kernel.org/r/20220511225517.407935-1-stephen.s.brennan@oracle.com/ # v1 Link: https://lore.kernel.org/r/20220512215045.489140-1-stephen.s.brennan@oracle.com/ # v2 Reviewed-by: Jarkko Sakkinen Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""

2022-05-25T06:41:22+00:00

commit 901c7280ca0d5e2b4a8929fbe0bfb007ac2a6544 upstream. Halil Pasic points out [1] that the full revert of that commit (revert in bddac7c1e02b), and that a partial revert that only reverts the problematic case, but still keeps some of the cleanups is probably better. And that partial revert [2] had already been verified by Oleksandr Natalenko to also fix the issue, I had just missed that in the long discussion. So let's reinstate the cleanups from commit aa6f8dcbab47 ("swiotlb: rework "fix info leak with DMA_FROM_DEVICE""), and effectively only revert the part that caused problems. Link: https://lore.kernel.org/all/20220328013731.017ae3e3.pasic@linux.ibm.com/ [1] Link: https://lore.kernel.org/all/20220324055732.GB12078@lst.de/ [2] Link: https://lore.kernel.org/all/4386660.LvFx2qVVIh@natalenko.name/ [3] Suggested-by: Halil Pasic Tested-by: Oleksandr Natalenko Cc: Christoph Hellwig" Signed-off-by: Linus Torvalds [OP: backport to 4.14: apply swiotlb_tbl_map_single() changes in lib/swiotlb.c] Signed-off-by: Ovidiu Panait Signed-off-by: Greg Kroah-Hartman

swiotlb: fix info leak with DMA_FROM_DEVICE

2022-05-25T06:41:22+00:00

commit ddbd89deb7d32b1fbb879f48d68fda1a8ac58e8e upstream. The problem I'm addressing was discovered by the LTP test covering cve-2018-1000204. A short description of what happens follows: 1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device. 2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO. 3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV). 4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer. 5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails. One can argue that this is an swiotlb problem, because without swiotlb we leak all zeros, and the swiotlb should be transparent in a sense that it does not affect the outcome (if all other participants are well behaved). Copying the content of the original buffer into the swiotlb buffer is the only way I can think of to make swiotlb transparent in such scenarios. So let's do just that if in doubt, but allow the driver to tell us that the whole mapped buffer is going to be overwritten, in which case we can preserve the old behavior and avoid the performance impact of the extra bounce. Signed-off-by: Halil Pasic Signed-off-by: Christoph Hellwig [OP: backport to 4.14: apply swiotlb_tbl_map_single() changes in lib/swiotlb.c] Signed-off-by: Ovidiu Panait Signed-off-by: Greg Kroah-Hartman

hex2bin: fix access beyond string end

2022-05-12T10:17:06+00:00

commit e4d8a29997731b3bb14059024b24df9f784288d0 upstream. If we pass too short string to "hex2bin" (and the string size without the terminating NUL character is even), "hex2bin" reads one byte after the terminating NUL character. This patch fixes it. Note that hex_to_bin returns -1 on error and hex2bin return -EINVAL on error - so we can't just return the variable "hi" or "lo" on error. This inconsistency may be fixed in the next merge window, but for the purpose of fixing this bug, we just preserve the existing behavior and return -1 and -EINVAL. Signed-off-by: Mikulas Patocka Reviewed-by: Andy Shevchenko Fixes: b78049831ffe ("lib: add error checking to hex2bin") Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

hex2bin: make the function hex_to_bin constant-time

2022-05-12T10:17:06+00:00

commit e5be15767e7e284351853cbaba80cde8620341fb upstream. The function hex2bin is used to load cryptographic keys into device mapper targets dm-crypt and dm-integrity. It should take constant time independent on the processed data, so that concurrently running unprivileged code can't infer any information about the keys via microarchitectural convert channels. This patch changes the function hex_to_bin so that it contains no branches and no memory accesses. Note that this shouldn't cause performance degradation because the size of the new function is the same as the size of the old function (on x86-64) - and the new function causes no branch misprediction penalties. I compile-tested this function with gcc on aarch64 alpha arm hppa hppa64 i386 ia64 m68k mips32 mips64 powerpc powerpc64 riscv sh4 s390x sparc32 sparc64 x86_64 and with clang on aarch64 arm hexagon i386 mips32 mips64 powerpc powerpc64 s390x sparc32 sparc64 x86_64 to verify that there are no branches in the generated code. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

lib/test: use after free in register_test_dev_kmod()

2022-04-20T07:08:21+00:00

[ Upstream commit dc0ce6cc4b133f5f2beb8b47dacae13a7d283c2c ] The "test_dev" pointer is freed but then returned to the caller. Fixes: d9c6a72d6fa2 ("kmod: add test driver to stress test the module loader") Signed-off-by: Dan Carpenter Signed-off-by: Luis Chamberlain Signed-off-by: Sasha Levin

lib/raid6/test: fix multiple definition linking error

2022-04-20T07:08:12+00:00

commit a5359ddd052860bacf957e65fe819c63e974b3a6 upstream. GCC 10+ defaults to -fno-common, which enforces proper declaration of external references using "extern". without this change a link would fail with: lib/raid6/test/algos.c:28: multiple definition of `raid6_call'; lib/raid6/test/test.c:22: first defined here the pq.h header that is included already includes an extern declaration so we can just remove the redundant one here. Cc: Signed-off-by: Dirk Müller Reviewed-by: Paul Menzel Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman

ARM: 9178/1: fix unmet dependency on BITREVERSE for HAVE_ARCH_BITREVERSE

2022-03-23T08:01:34+00:00

[ Upstream commit 11c57c3ba94da74c3446924260e34e0b1950b5d7 ] Resending this to properly add it to the patch tracker - thanks for letting me know, Arnd :) When ARM is enabled, and BITREVERSE is disabled, Kbuild gives the following warning: WARNING: unmet direct dependencies detected for HAVE_ARCH_BITREVERSE Depends on [n]: BITREVERSE [=n] Selected by [y]: - ARM [=y] && (CPU_32v7M [=n] || CPU_32v7 [=y]) && !CPU_32v6 [=n] This is because ARM selects HAVE_ARCH_BITREVERSE without selecting BITREVERSE, despite HAVE_ARCH_BITREVERSE depending on BITREVERSE. This unmet dependency bug was found by Kismet, a static analysis tool for Kconfig. Please advise if this is not the appropriate solution. Signed-off-by: Julian Braha Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin