CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2024-50066 – mm/mremap: fix move_normal_pmd/retract_page_tables race
https://notcve.org/view.php?id=CVE-2024-50066
In the Linux kernel, the following vulnerability has been resolved: mm/mremap: fix move_normal_pmd/retract_page_tables race In mremap(), move_page_tables() looks at the type of the PMD entry and the specified address range to figure out by which method the next chunk of page table entries should be moved. At that point, the mmap_lock is held in write mode, but no rmap locks are held yet. For PMD entries that point to page tables and are fully covered by the source address range, move_pgt_entry(NORMAL_PMD, ...) is called, which first takes rmap locks, then does move_normal_pmd(). move_normal_pmd() takes the necessary page table locks at source and destination, then moves an entire page table from the source to the destination. The problem is: The rmap locks, which protect against concurrent page table removal by retract_page_tables() in the THP code, are only taken after the PMD entry has been read and it has been decided how to move it. So we can race as follows (with two processes that have mappings of the same tmpfs file that is stored on a tmpfs mount with huge=advise); note that process A accesses page tables through the MM while process B does it through the file rmap: process A process B ========= ========= mremap mremap_to move_vma move_page_tables get_old_pmd alloc_new_pmd *** PREEMPT *** madvise(MADV_COLLAPSE) do_madvise madvise_walk_vmas madvise_vma_behavior madvise_collapse hpage_collapse_scan_file collapse_file retract_page_tables i_mmap_lock_read(mapping) pmdp_collapse_flush i_mmap_unlock_read(mapping) move_pgt_entry(NORMAL_PMD, ...) take_rmap_locks move_normal_pmd drop_rmap_locks When this happens, move_normal_pmd() can end up creating bogus PMD entries in the line `pmd_populate(mm, new_pmd, pmd_pgtable(pmd))`. The effect depends on arch-specific and machine-specific details; on x86, you can end up with physical page 0 mapped as a page table, which is likely exploitable for user->kernel privilege escalation. Fix the race by letting process B recheck that the PMD still points to a page table after the rmap locks have been taken. Otherwise, we bail and let the caller fall back to the PTE-level copying path, which will then bail immediately at the pmd_none() check. Bug reachability: Reaching this bug requires that you can create shmem/file THP mappings - anonymous THP uses different code that doesn't zap stuff under rmap locks. File THP is gated on an experimental config flag (CONFIG_READ_ONLY_THP_FOR_FS), so on normal distro kernels you need shmem THP to hit this bug. • https://git.kernel.org/stable/c/1d65b771bc08cd054cf6d3766a72e113dc46d62f https://git.kernel.org/stable/c/17396e32f975130b3e6251f024c8807d192e4c3e https://git.kernel.org/stable/c/1552ce9ce8af47c0fe911682e5e1855e25851ca9 https://git.kernel.org/stable/c/6fa1066fc5d00cb9f1b0e83b7ff6ef98d26ba2aa •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2023-52919 – nfc: nci: fix possible NULL pointer dereference in send_acknowledge()
https://notcve.org/view.php?id=CVE-2023-52919
In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix possible NULL pointer dereference in send_acknowledge() Handle memory allocation failure from nci_skb_alloc() (calling alloc_skb()) to avoid possible NULL pointer dereference. • https://git.kernel.org/stable/c/391d8a2da787257aeaf952c974405b53926e3fb3 https://git.kernel.org/stable/c/2b2edf089df3a69f0072c6e71563394c5a94e62e https://git.kernel.org/stable/c/5622592f8f74ae3e594379af02e64ea84772d0dd https://git.kernel.org/stable/c/76050b0cc5a72e0c7493287b7e18e1cb9e3c4612 https://git.kernel.org/stable/c/c95fa5b20fe03609e0894656fa43c18045b5097e https://git.kernel.org/stable/c/ffdc881f68073ff86bf21afb9bb954812e8278be https://git.kernel.org/stable/c/d7dbdbe3800a908eecd4975c31be47dd45e2104a https://git.kernel.org/stable/c/bb6cacc439ddd2cd51227ab193f4f91cf •
CVSS: -EPSS: 0%CPEs: 7EXPL: 0CVE-2023-52918 – media: pci: cx23885: check cx23885_vdev_init() return
https://notcve.org/view.php?id=CVE-2023-52918
In the Linux kernel, the following vulnerability has been resolved: media: pci: cx23885: check cx23885_vdev_init() return cx23885_vdev_init() can return a NULL pointer, but that pointer is used in the next line without a check. Add a NULL pointer check and go to the error unwind if it is NULL. • https://git.kernel.org/stable/c/8e31b096e2e1949bc8f0be019c9ae70d414404c6 https://git.kernel.org/stable/c/199a42fc4c45e8b7f19efeb15dbc36889a599ac2 https://git.kernel.org/stable/c/e7385510e2550a9f8b6f3d5f33c5b894ab9ba976 https://git.kernel.org/stable/c/a5f1d30c51c485cec7a7de60205667c3ff86c303 https://git.kernel.org/stable/c/06ee04a907d64ee3910fecedd05d7f1be4b1b70e https://git.kernel.org/stable/c/b1397fb4a779fca560c43d2acf6702d41b4a495b https://git.kernel.org/stable/c/15126b916e39b0cb67026b0af3c014bfeb1f76b3 •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2022-49033 – btrfs: qgroup: fix sleep from invalid context bug in btrfs_qgroup_inherit()
https://notcve.org/view.php?id=CVE-2022-49033
In the Linux kernel, the following vulnerability has been resolved: btrfs: qgroup: fix sleep from invalid context bug in btrfs_qgroup_inherit() Syzkaller reported BUG as follows: BUG: sleeping function called from invalid context at include/linux/sched/mm.h:274 Call Trace: <TASK> dump_stack_lvl+0xcd/0x134 __might_resched.cold+0x222/0x26b kmem_cache_alloc+0x2e7/0x3c0 update_qgroup_limit_item+0xe1/0x390 btrfs_qgroup_inherit+0x147b/0x1ee0 create_subvol+0x4eb/0x1710 btrfs_mksubvol+0xfe5/0x13f0 __btrfs_ioctl_snap_create+0x2b0/0x430 btrfs_ioctl_snap_create_v2+0x25a/0x520 btrfs_ioctl+0x2a1c/0x5ce0 __x64_sys_ioctl+0x193/0x200 do_syscall_64+0x35/0x80 Fix this by calling qgroup_dirty() on @dstqgroup, and update limit item in btrfs_run_qgroups() later outside of the spinlock context. • https://git.kernel.org/stable/c/89840b12c8fad7200eb6478525c13261512c01be https://git.kernel.org/stable/c/3c98e91be6aea4c7acf09da6eb0c107ea9186bb5 https://git.kernel.org/stable/c/f4b930a1602b05e77fee31f9616599b25e910a86 https://git.kernel.org/stable/c/8eb912af525042a7365295eb62f6d5270c2a6462 https://git.kernel.org/stable/c/01d7c41eac9129fba80d8aed0060caab4a7dbe09 https://git.kernel.org/stable/c/044da1a371a0da579e805e89c96865f62d8f6f69 https://git.kernel.org/stable/c/588ae4fdd8b11788a797776b10d6c44ae12bc133 https://git.kernel.org/stable/c/f7e942b5bb35d8e3af54053d19a6bf041 •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2022-49032 – iio: health: afe4404: Fix oob read in afe4404_[read|write]_raw
https://notcve.org/view.php?id=CVE-2022-49032
In the Linux kernel, the following vulnerability has been resolved: iio: health: afe4404: Fix oob read in afe4404_[read|write]_raw KASAN report out-of-bounds read as follows: BUG: KASAN: global-out-of-bounds in afe4404_read_raw+0x2ce/0x380 Read of size 4 at addr ffffffffc00e4658 by task cat/278 Call Trace: afe4404_read_raw iio_read_channel_info dev_attr_show The buggy address belongs to the variable: afe4404_channel_leds+0x18/0xffffffffffffe9c0 This issue can be reproduce by singe command: $ cat /sys/bus/i2c/devices/0-0058/iio\:device0/in_intensity6_raw The array size of afe4404_channel_leds and afe4404_channel_offdacs are less than channels, so access with chan->address cause OOB read in afe4404_[read|write]_raw. Fix it by moving access before use them. • https://git.kernel.org/stable/c/b36e8257641a043764c62240316610c81e36376c https://git.kernel.org/stable/c/68de7da092f38395dde523f2e5db26eba6c23e28 https://git.kernel.org/stable/c/113c08030a89aaf406f8a1d4549d758a67c2afba https://git.kernel.org/stable/c/f5575041ec15310bdc50c42b8b22118cc900226e https://git.kernel.org/stable/c/3f566b626029ca8598d48e5074e56bb37399ca1b https://git.kernel.org/stable/c/5eb114f55b37dbc0487aa9c1913b81bb7837f1c4 https://git.kernel.org/stable/c/f7419fc42afc035f6b29ce713e17dcd2000c833f https://git.kernel.org/stable/c/d45d9f45e7b1365fd0d9bf14680d6d508 •