kernel/linux.git, branch v6.12.50

Linux 6.12.50

2025-10-02T11:44:15+00:00

Link: https://lore.kernel.org/r/20250930143821.852512002@linuxfoundation.org Tested-by: Brett A C Sheffield Tested-by: Florian Fainelli Tested-by: Peter Schneider Tested-by: Ron Economos Tested-by: Salvatore Bonaccorso Tested-by: Jon Hunter Tested-by: Mark Brown Tested-by: Linux Kernel Functional Testing Tested-by: Brett Mastbergen Tested-by: Shuah Khan Tested-by: Miguel Ojeda Tested-by: Pascal Ernster Signed-off-by: Greg Kroah-Hartman

drm/i915/backlight: Return immediately when scale() finds invalid parameters

2025-10-02T11:44:15+00:00

commit 6f71507415841d1a6d38118e5fa0eaf0caab9c17 upstream. The scale() functions detects invalid parameters, but continues its calculations anyway. This causes bad results if negative values are used for unsigned operations. Worst case, a division by 0 error will be seen if source_min == source_max. On top of that, after v6.13, the sequence of WARN_ON() followed by clamp() may result in a build error with gcc 13.x. drivers/gpu/drm/i915/display/intel_backlight.c: In function 'scale': include/linux/compiler_types.h:542:45: error: call to '__compiletime_assert_415' declared with attribute error: clamp() low limit source_min greater than high limit source_max This happens if the compiler decides to rearrange the code as follows. if (source_min > source_max) { WARN(..); /* Do the clamp() knowing that source_min > source_max */ source_val = clamp(source_val, source_min, source_max); } else { /* Do the clamp knowing that source_min <= source_max */ source_val = clamp(source_val, source_min, source_max); } Fix the problem by evaluating the return values from WARN_ON and returning immediately after a warning. While at it, fix divide by zero error seen if source_min == source_max. Analyzed-by: Linus Torvalds Suggested-by: Linus Torvalds Suggested-by: David Laight Cc: David Laight Cc: Jani Nikula Cc: Andy Shevchenko Signed-off-by: Guenter Roeck Reviewed-by: Rodrigo Vivi Link: https://patchwork.freedesktop.org/patch/msgid/20250121145203.2851237-1-linux@roeck-us.net Signed-off-by: Rodrigo Vivi Signed-off-by: Greg Kroah-Hartman

Revert "usb: xhci: remove option to change a default ring's TRB cycle bit"

2025-10-02T11:44:15+00:00

Revert commit 9b28ef1e4cc07cdb35da257aa4358d0127168b68 which is upstream commit e1b0fa863907a61e86acc19ce2d0633941907c8e It causes regression in 6.12.49 stable, no issues in upstream. Commit 9b28ef1e4cc0 ("usb: xhci: remove option to change a default ring's TRB cycle bit") introduced a regression in 6.12.49 stable kernel. The original commit was never intended for stable kernels, but was added as a dependency for commit a5c98e8b1398 ("xhci: dbc: Fix full DbC transfer ring after several reconnects"). Since this commit is more of an optimization, revert it and solve the dependecy by modifying one line in xhci_dbc_ring_init(). Specifically, commit a5c98e8b1398 ("xhci: dbc: Fix full DbC transfer ring after several reconnects") moved function call xhci_initialize_ring_info() into a separate function. To resolve the dependency, the arguments for this function call are also reverted. Closes: https://lore.kernel.org/stable/01b8c8de46251cfaad1329a46b7e3738@stwm.de/ Tested-by: Wolfgang Walter Cc: stable@vger.kernel.org # v6.12.49 Signed-off-by: Niklas Neronin Acked-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman

iommufd: Fix race during abort for file descriptors

2025-10-02T11:44:15+00:00

[ Upstream commit 4e034bf045b12852a24d5d33f2451850818ba0c1 ] fput() doesn't actually call file_operations release() synchronously, it puts the file on a work queue and it will be released eventually. This is normally fine, except for iommufd the file and the iommufd_object are tied to gether. The file has the object as it's private_data and holds a users refcount, while the object is expected to remain alive as long as the file is. When the allocation of a new object aborts before installing the file it will fput() the file and then go on to immediately kfree() the obj. This causes a UAF once the workqueue completes the fput() and tries to decrement the users refcount. Fix this by putting the core code in charge of the file lifetime, and call __fput_sync() during abort to ensure that release() is called before kfree. __fput_sync() is a bit too tricky to open code in all the object implementations. Instead the objects tell the core code where the file pointer is and the core will take care of the life cycle. If the object is successfully allocated then the file will hold a users refcount and the iommufd_object cannot be destroyed. It is worth noting that close(); ioctl(IOMMU_DESTROY); doesn't have an issue because close() is already using a synchronous version of fput(). The UAF looks like this: BUG: KASAN: slab-use-after-free in iommufd_eventq_fops_release+0x45/0xc0 drivers/iommu/iommufd/eventq.c:376 Write of size 4 at addr ffff888059c97804 by task syz.0.46/6164 CPU: 0 UID: 0 PID: 6164 Comm: syz.0.46 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline] __refcount_dec include/linux/refcount.h:455 [inline] refcount_dec include/linux/refcount.h:476 [inline] iommufd_eventq_fops_release+0x45/0xc0 drivers/iommu/iommufd/eventq.c:376 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x41c/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Link: https://patch.msgid.link/r/1-v1-02cd136829df+31-iommufd_syz_fput_jgg@nvidia.com Cc: stable@vger.kernel.org Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object") Reviewed-by: Nicolin Chen Reviewed-by: Nirmoy Das Reviewed-by: Kevin Tian Tested-by: Nicolin Chen Reported-by: syzbot+80620e2d0d0a33b09f93@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/68c8583d.050a0220.2ff435.03a2.GAE@google.com Signed-off-by: Jason Gunthorpe [ applied eventq.c changes to fault.c, drop veventq bits ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

fbcon: Fix OOB access in font allocation

2025-10-02T11:44:14+00:00

commit 9b2f5ef00e852f8e8902a4d4f73aeedc60220c12 upstream. Commit 1a194e6c8e1e ("fbcon: fix integer overflow in fbcon_do_set_font") introduced an out-of-bounds access by storing data and allocation sizes in the same variable. Restore the old size calculation and use the new variable 'alloc_size' for the allocation. Signed-off-by: Thomas Zimmermann Fixes: 1a194e6c8e1e ("fbcon: fix integer overflow in fbcon_do_set_font") Reported-by: Jani Nikula Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15020 Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6201 Cc: Samasth Norway Ananda Cc: Thomas Zimmermann Cc: George Kennedy Cc: Greg Kroah-Hartman Cc: Simona Vetter Cc: Helge Deller Cc: "Ville Syrjälä" Cc: Sam Ravnborg Cc: Qianqiang Liu Cc: Shixiong Ou Cc: Kees Cook Cc: # v5.9+ Cc: Zsolt Kajtar Reviewed-by: Lucas De Marchi Reviewed-by: Qianqiang Liu Link: https://lore.kernel.org/r/20250922134619.257684-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman

fbcon: fix integer overflow in fbcon_do_set_font

2025-10-02T11:44:14+00:00

commit 1a194e6c8e1ee745e914b0b7f50fa86c89ed13fe upstream. Fix integer overflow vulnerabilities in fbcon_do_set_font() where font size calculations could overflow when handling user-controlled font parameters. The vulnerabilities occur when: 1. CALC_FONTSZ(h, pitch, charcount) performs h * pith * charcount multiplication with user-controlled values that can overflow. 2. FONT_EXTRA_WORDS * sizeof(int) + size addition can also overflow 3. This results in smaller allocations than expected, leading to buffer overflows during font data copying. Add explicit overflow checking using check_mul_overflow() and check_add_overflow() kernel helpers to safety validate all size calculations before allocation. Signed-off-by: Samasth Norway Ananda Reviewed-by: Thomas Zimmermann Fixes: 39b3cffb8cf3 ("fbcon: prevent user font height or width change from causing potential out-of-bounds access") Cc: George Kennedy Cc: stable Cc: syzbot+38a3699c7eaf165b97a6@syzkaller.appspotmail.com Cc: Greg Kroah-Hartman Cc: Simona Vetter Cc: Helge Deller Cc: Thomas Zimmermann Cc: "Ville Syrjälä" Cc: Sam Ravnborg Cc: Qianqiang Liu Cc: Shixiong Ou Cc: Kees Cook Cc: # v5.9+ Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/r/20250912170023.3931881-1-samasth.norway.ananda@oracle.com Signed-off-by: Greg Kroah-Hartman

mm/hugetlb: fix folio is still mapped when deleted

2025-10-02T11:44:14+00:00

commit 7b7387650dcf2881fd8bb55bcf3c8bd6c9542dd7 upstream. Migration may be raced with fallocating hole. remove_inode_single_folio will unmap the folio if the folio is still mapped. However, it's called without folio lock. If the folio is migrated and the mapped pte has been converted to migration entry, folio_mapped() returns false, and won't unmap it. Due to extra refcount held by remove_inode_single_folio, migration fails, restores migration entry to normal pte, and the folio is mapped again. As a result, we triggered BUG in filemap_unaccount_folio. The log is as follows: BUG: Bad page cache in process hugetlb pfn:156c00 page: refcount:515 mapcount:0 mapping:0000000099fef6e1 index:0x0 pfn:0x156c00 head: order:9 mapcount:1 entire_mapcount:1 nr_pages_mapped:0 pincount:0 aops:hugetlbfs_aops ino:dcc dentry name(?):"my_hugepage_file" flags: 0x17ffffc00000c1(locked|waiters|head|node=0|zone=2|lastcpupid=0x1fffff) page_type: f4(hugetlb) page dumped because: still mapped when deleted CPU: 1 UID: 0 PID: 395 Comm: hugetlb Not tainted 6.17.0-rc5-00044-g7aac71907bde-dirty #484 NONE Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 Call Trace: dump_stack_lvl+0x4f/0x70 filemap_unaccount_folio+0xc4/0x1c0 __filemap_remove_folio+0x38/0x1c0 filemap_remove_folio+0x41/0xd0 remove_inode_hugepages+0x142/0x250 hugetlbfs_fallocate+0x471/0x5a0 vfs_fallocate+0x149/0x380 Hold folio lock before checking if the folio is mapped to avold race with migration. Link: https://lkml.kernel.org/r/20250912074139.3575005-1-tujinjiang@huawei.com Fixes: 4aae8d1c051e ("mm/hugetlbfs: unmap pages if page fault raced with hole punch") Signed-off-by: Jinjiang Tu Cc: David Hildenbrand Cc: Kefeng Wang Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Oscar Salvador Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

kmsan: fix out-of-bounds access to shadow memory

2025-10-02T11:44:14+00:00

commit 85e1ff61060a765d91ee62dc5606d4d547d9d105 upstream. Running sha224_kunit on a KMSAN-enabled kernel results in a crash in kmsan_internal_set_shadow_origin(): BUG: unable to handle page fault for address: ffffbc3840291000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 1810067 P4D 1810067 PUD 192d067 PMD 3c17067 PTE 0 Oops: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 81 Comm: kunit_try_catch Tainted: G N 6.17.0-rc3 #10 PREEMPT(voluntary) Tainted: [N]=TEST Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 RIP: 0010:kmsan_internal_set_shadow_origin+0x91/0x100 [...] Call Trace: __msan_memset+0xee/0x1a0 sha224_final+0x9e/0x350 test_hash_buffer_overruns+0x46f/0x5f0 ? kmsan_get_shadow_origin_ptr+0x46/0xa0 ? __pfx_test_hash_buffer_overruns+0x10/0x10 kunit_try_run_case+0x198/0xa00 This occurs when memset() is called on a buffer that is not 4-byte aligned and extends to the end of a guard page, i.e. the next page is unmapped. The bug is that the loop at the end of kmsan_internal_set_shadow_origin() accesses the wrong shadow memory bytes when the address is not 4-byte aligned. Since each 4 bytes are associated with an origin, it rounds the address and size so that it can access all the origins that contain the buffer. However, when it checks the corresponding shadow bytes for a particular origin, it incorrectly uses the original unrounded shadow address. This results in reads from shadow memory beyond the end of the buffer's shadow memory, which crashes when that memory is not mapped. To fix this, correctly align the shadow address before accessing the 4 shadow bytes corresponding to each origin. Link: https://lkml.kernel.org/r/20250911195858.394235-1-ebiggers@kernel.org Fixes: 2ef3cec44c60 ("kmsan: do not wipe out origin when doing partial unpoisoning") Signed-off-by: Eric Biggers Tested-by: Alexander Potapenko Reviewed-by: Alexander Potapenko Cc: Dmitriy Vyukov Cc: Marco Elver Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

gpiolib: Extend software-node support to support secondary software-nodes

2025-10-02T11:44:14+00:00

commit c6ccc4dde17676dfe617b9a37bd9ba19a8fc87ee upstream. When a software-node gets added to a device which already has another fwnode as primary node it will become the secondary fwnode for that device. Currently if a software-node with GPIO properties ends up as the secondary fwnode then gpiod_find_by_fwnode() will fail to find the GPIOs. Add a new gpiod_fwnode_lookup() helper which falls back to calling gpiod_find_by_fwnode() with the secondary fwnode if the GPIO was not found in the primary fwnode. Fixes: e7f9ff5dc90c ("gpiolib: add support for software nodes") Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede Reviewed-by: Dmitry Torokhov Link: https://lore.kernel.org/r/20250920200955.20403-1-hansg@kernel.org Signed-off-by: Bartosz Golaszewski Signed-off-by: Greg Kroah-Hartman

fs/proc/task_mmu: check p->vec_buf for NULL

2025-10-02T11:44:14+00:00

commit 28aa29986dde79e8466bc87569141291053833f5 upstream. When the PAGEMAP_SCAN ioctl is invoked with vec_len = 0 reaches pagemap_scan_backout_range(), kernel panics with null-ptr-deref: [ 44.936808] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI [ 44.937797] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 44.938391] CPU: 1 UID: 0 PID: 2480 Comm: reproducer Not tainted 6.17.0-rc6 #22 PREEMPT(none) [ 44.939062] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 44.939935] RIP: 0010:pagemap_scan_thp_entry.isra.0+0x741/0xa80 [ 44.946828] Call Trace: [ 44.947030] [ 44.949219] pagemap_scan_pmd_entry+0xec/0xfa0 [ 44.952593] walk_pmd_range.isra.0+0x302/0x910 [ 44.954069] walk_pud_range.isra.0+0x419/0x790 [ 44.954427] walk_p4d_range+0x41e/0x620 [ 44.954743] walk_pgd_range+0x31e/0x630 [ 44.955057] __walk_page_range+0x160/0x670 [ 44.956883] walk_page_range_mm+0x408/0x980 [ 44.958677] walk_page_range+0x66/0x90 [ 44.958984] do_pagemap_scan+0x28d/0x9c0 [ 44.961833] do_pagemap_cmd+0x59/0x80 [ 44.962484] __x64_sys_ioctl+0x18d/0x210 [ 44.962804] do_syscall_64+0x5b/0x290 [ 44.963111] entry_SYSCALL_64_after_hwframe+0x76/0x7e vec_len = 0 in pagemap_scan_init_bounce_buffer() means no buffers are allocated and p->vec_buf remains set to NULL. This breaks an assumption made later in pagemap_scan_backout_range(), that page_region is always allocated for p->vec_buf_index. Fix it by explicitly checking p->vec_buf for NULL before dereferencing. Other sites that might run into same deref-issue are already (directly or transitively) protected by checking p->vec_buf. Note: From PAGEMAP_SCAN man page, it seems vec_len = 0 is valid when no output is requested and it's only the side effects caller is interested in, hence it passes check in pagemap_scan_get_args(). This issue was found by syzkaller. Link: https://lkml.kernel.org/r/20250922082206.6889-1-acsjakub@amazon.de Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") Signed-off-by: Jakub Acs Reviewed-by: Muhammad Usama Anjum Acked-by: David Hildenbrand Cc: Vlastimil Babka Cc: Lorenzo Stoakes Cc: Jinjiang Tu Cc: Suren Baghdasaryan Cc: Penglei Jiang Cc: Mark Brown Cc: Baolin Wang Cc: Ryan Roberts Cc: Andrei Vagin Cc: "Michał Mirosław" Cc: Stephen Rothwell Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman