{"uuid": "27d2509a-1752-4495-be4d-288178750957", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "2a075640-a300-48a4-bb44-bc6130783b9b", "vulnerability": "CVE-2024-46785", "type": "published-proof-of-concept", "source": "https://t.me/cvedetector/5947", "content": "{\n  \"Source\": \"CVE FEED\",\n  \"Title\": \"CVE-2024-46785 - Linux Eventfs Null Pointer Dereference Vulnerability\", \n  \"Content\": \"CVE ID : CVE-2024-46785 \nPublished : Sept. 18, 2024, 8:15 a.m. | 35\u00a0minutes ago \nDescription : In the Linux kernel, the following vulnerability has been resolved:  \n  \neventfs: Use list_del_rcu() for SRCU protected list variable  \n  \nChi Zhiling reported:  \n  \n  We found a null pointer accessing in tracefs[1], the reason is that the  \n  variable 'ei_child' is set to LIST_POISON1, that means the list was  \n  removed in eventfs_remove_rec. so when access the ei_child->is_freed, the  \n  panic triggered.  \n  \n  by the way, the following script can reproduce this panic  \n  \n  loop1 (){  \n      while true  \n      do  \n          echo \"p:kp submit_bio\" > /sys/kernel/debug/tracing/kprobe_events  \n          echo \"\" > /sys/kernel/debug/tracing/kprobe_events  \n      done  \n  }  \n  loop2 (){  \n      while true  \n      do  \n          tree /sys/kernel/debug/tracing/events/kprobes/  \n      done  \n  }  \n  loop1 &  \n  loop2  \n  \n  [1]:  \n  [ 1147.959632][T17331] Unable to handle kernel paging request at virtual address dead000000000150  \n  [ 1147.968239][T17331] Mem abort info:  \n  [ 1147.971739][T17331]   ESR = 0x0000000096000004  \n  [ 1147.976172][T17331]   EC = 0x25: DABT (current EL), IL = 32 bits  \n  [ 1147.982171][T17331]   SET = 0, FnV = 0  \n  [ 1147.985906][T17331]   EA = 0, S1PTW = 0  \n  [ 1147.989734][T17331]   FSC = 0x04: level 0 translation fault  \n  [ 1147.995292][T17331] Data abort info:  \n  [ 1147.998858][T17331]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000  \n  [ 1148.005023][T17331]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0  \n  [ 1148.010759][T17331]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0  \n  [ 1148.016752][T17331] [dead000000000150] address between user and kernel address ranges  \n  [ 1148.024571][T17331] Internal error: Oops: 0000000096000004 [#1] SMP  \n  [ 1148.030825][T17331] Modules linked in: team_mode_loadbalance team nlmon act_gact cls_flower sch_ingress bonding tls macvlan dummy ib_core bridge stp llc veth amdgpu amdxcp mfd_core gpu_sched drm_exec drm_buddy radeon crct10dif_ce video drm_suballoc_helper ghash_ce drm_ttm_helper sha2_ce ttm sha256_arm64 i2c_algo_bit sha1_ce sbsa_gwdt cp210x drm_display_helper cec sr_mod cdrom drm_kms_helper binfmt_misc sg loop fuse drm dm_mod nfnetlink ip_tables autofs4 [last unloaded: tls]  \n  [ 1148.072808][T17331] CPU: 3 PID: 17331 Comm: ls Tainted: G        W         ------- ----  6.6.43 #2  \n  [ 1148.081751][T17331] Source Version: 21b3b386e948bedd29369af66f3e98ab01b1c650  \n  [ 1148.088783][T17331] Hardware name: Greatwall GW-001M1A-FTF/GW-001M1A-FTF, BIOS KunLun BIOS V4.0 07/16/2020  \n  [ 1148.098419][T17331] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)  \n  [ 1148.106060][T17331] pc : eventfs_iterate+0x2c0/0x398  \n  [ 1148.111017][T17331] lr : eventfs_iterate+0x2fc/0x398  \n  [ 1148.115969][T17331] sp : ffff80008d56bbd0  \n  [ 1148.119964][T17331] x29: ffff80008d56bbf0 x28: ffff001ff5be2600 x27: 0000000000000000  \n  [ 1148.127781][T17331] x26: ffff001ff52ca4e0 x25: 0000000000009977 x24: dead000000000100  \n  [ 1148.135598][T17331] x23: 0000000000000000 x22: 000000000000000b x21: ffff800082645f10  \n  [ 1148.143415][T17331] x20: ffff001fddf87c70 x19: ffff80008d56bc90 x18: 0000000000000000  \n  [ 1148.151231][T17331] x17: 0000000000000000 x16: 0000000000000000 x15: ffff001ff52ca4e0  \n  [ 1148.159048][T17331] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000  \n  [ 1148.166864][T17331] x11: 0000000000000000 x10: 0000000000000000 x9 : ffff8000804391d0  \n  [ 1148.174680][T17331] x8 : 0000000180000000 x7 : 0000000000000018 x6 : 0000aaab04b92862  \n  [ 1148.182498][T17331] x5 : 0000aaab04b92862 x4 : 0000000080000000 x3 : 0000000000000068  \n  [ 1148.190314][T17331] x2 : 000000000000000f x1 : 0000000000007ea8 x0 : 0000000000000001  \n  [ 1148.198131][T17331] Call trace:  \n  [ 1148.201259][T17331]  eventfs_iterate+0x2c0/0x398  \n  [ 1148.205864][T17331]  iterate_dir+0x98/0x188  \n  [ 1[...]", "creation_timestamp": "2024-09-18T10:53:25.000000Z"}