cbcvebase.
CVE-2024-56592
published 2024-12-27

CVE-2024-56592: In the Linux kernel, the following vulnerability has been resolved: bpf: Call free_htab_elem() after htab_unlock_bucket() For htab of maps, when the map is…

PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.22%
12.2th percentile
In the Linux kernel, the following vulnerability has been resolved: bpf: Call free_htab_elem() after htab_unlock_bucket() For htab of maps, when the map is removed from the htab, it may hold the last reference of the map. bpf_map_fd_put_ptr() will invoke bpf_map_free_id() to free the id of the removed map element. However, bpf_map_fd_put_ptr() is invoked while holding a bucket lock (raw_spin_lock_t), and bpf_map_free_id() attempts to acquire map_idr_lock (spinlock_t), triggering the following lockdep warning: [ BUG: Invalid wait context ] 6.11.0-rc4+ #49 Not tainted test_maps/4881 is trying to lock: ffffffff84884578 (map_idr_lock){+...}-{3:3}, at: bpf_map_free_id.part.0+0x21/0x70 other info that might help us debug this: context-{5:5} 2 locks held by test_maps/4881: #0: ffffffff846caf60 (rcu_read_lock){....}-{1:3}, at: bpf_fd_htab_map_update_elem+0xf9/0x270 #1: ffff888149ced148 (&htab->lockdep_key#2){....}-{2:2}, at: htab_map_update_elem+0x178/0xa80 stack backtrace: CPU: 0 UID: 0 PID: 4881 Comm: test_maps Not tainted 6.11.0-rc4+ #49 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... Call Trace: dump_stack_lvl+0x6e/0xb0 dump_stack+0x10/0x20 __lock_acquire+0x73e/0x36c0 lock_acquire+0x182/0x450 _raw_spin_lock_irqsave+0x43/0x70 bpf_map_free_id.part.0+0x21/0x70 bpf_map_put+0xcf/0x110 bpf_map_fd_put_ptr+0x9a/0xb0 free_htab_elem+0x69/0xe0 htab_map_update_elem+0x50f/0xa80 bpf_fd_htab_map_update_elem+0x131/0x270 htab_map_update_elem+0x50f/0xa80 bpf_fd_htab_map_update_elem+0x131/0x270 bpf_map_update_value+0x266/0x380 __sys_bpf+0x21bb/0x36b0 __x64_sys_bpf+0x45/0x60 x64_sys_call+0x1b2a/0x20d0 do_syscall_64+0x5d/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e One way to fix the lockdep warning is using raw_spinlock_t for map_idr_lock as well. However, bpf_map_alloc_id() invokes idr_alloc_cyclic() after acquiring map_idr_lock, it will trigger a similar lockdep warning because the slab's lock (s->cpu_slab->lock) is still a spinlock. Instead of changing map_idr_lock's

Affected

13 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.12.5-1 (forky)linux 6.12.5-1 (forky)
linuxlinux
linuxlinux>= f3f1c054c288bb6e503005e6d73611151ed20e91 < 10e8a2dec9ff1b81de8e892b0850924038adbc6d10e8a2dec9ff1b81de8e892b0850924038adbc6d
linuxlinux>= f3f1c054c288bb6e503005e6d73611151ed20e91 < a50b4aa3007e63a590d501341f304676ebc74b3ba50b4aa3007e63a590d501341f304676ebc74b3b
linuxlinux>= f3f1c054c288bb6e503005e6d73611151ed20e91 < b9e9ed90b10c82a4e9d4d70a2890f06bfcdd3b78b9e9ed90b10c82a4e9d4d70a2890f06bfcdd3b78
linuxlinux_kernel>= 0 < 6.12.5-16.12.5-1
linuxlinux_kernel>= 0 < 6.12.5-16.12.5-1
linuxlinux_kernel>= 0 < 6.8.0-58.606.8.0-58.60
linuxlinux_kernel>= 4.13 < 6.6.666.6.66
linuxlinux_kernel>= 6.7 < 6.12.56.12.5
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.200.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.202.1-1_on_cbl_mariner_2.0

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
vendor_msrc4.4MEDIUM
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