Divide By Zero

In the Linux kernel, the following vulnerability has been resolved: video: fbdev: cirrusfb: check pixclock to avoid divide by zero Do a sanity check on pixclock value to avoid divide by zero. If the pixclock value is zero, the cirrusfb driver will round up pixclock to get the derived frequency as close to maxclock as possible. Syzkaller reported a divide error in cirrusfb_check_pixclock. divide error: 0000 [#1] SMP KASAN PTI CPU: 0 PID: 14938 Comm: cirrusfb_test Not tainted 5.15.0-rc6 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2 RIP: 0010:cirrusfb_check_var+0x6f1/0x1260 Call Trace: fb_set_var+0x398/0xf90 do_fb_ioctl+0x4b8/0x6f0 fb_ioctl+0xeb/0x130 __x64_sys_ioctl+0x19d/0x220 do_syscall_64+0x3a/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xaeShow less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Initialize denominator defaults to 1 [WHAT & HOW] Variables, used as denominators and maybe not assigned to other values, should be initialized to non-zero to avoid DIVIDE_BY_ZERO, as reported by Coverity. (cherry picked from commit e2c4c6c10542ccfe4a0830bb6c9fd5b177b7bbb7)Show less

In the Linux kernel, the following vulnerability has been resolved: gve: guard XDP xmit NDO on existence of xdp queues In GVE, dedicated XDP queues only exist when an XDP program is installed and the interface is up. As such, the NDO XDP XMIT callback should return early if either of these conditions are false. In the case of no loaded XDP program, priv->num_xdp_queues=0 which can cause a divide-by-zero error, and in the case of interface down, num_xdp_queues remains untouched to persist XDP queue count for the next interface up, but the TX pointer itself would be NULL. The XDP xmit callback also needs to synchronize with a device transitioning from open to close. This synchronization will happen via the GVE_PRIV_FLAGS_NAPI_ENABLED bit along with a synchronize_net() call, which waits for any RCU critical sections at call-time to complete.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add check for granularity in dml ceil/floor helpers [Why] Wrapper functions for dcn_bw_ceil2() and dcn_bw_floor2() should check for granularity is non zero to avoid assert and divide-by-zero error in dcn_bw_ functions. [How] Add check for granularity 0. (cherry picked from commit f6e09701c3eb2ccb8cb0518e0b67f1c69742a4ec)Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: fix divide error in DM plane scale calcs dm_get_plane_scale doesn't take into account plane scaled size equal to zero, leading to a kernel oops due to division by zero. Fix by setting out-scale size as zero when the dst size is zero, similar to what is done by drm_calc_scale(). This issue started with the introduction of cursor ovelay mode that uses this function to assess cursor mode changes via dm_crtc_get_cursor_mode() before checking plane state. [Dec17 17:14] Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI [ +0.000018] CPU: 5 PID: 1660 Comm: surface-DP-1 Not tainted 6.10.0+ #231 [ +0.000007] Hardware name: Valve Jupiter/Jupiter, BIOS F7A0131 01/30/2024 [ +0.000004] RIP: 0010:dm_get_plane_scale+0x3f/0x60 [amdgpu] [ +0.000553] Code: 44 0f b7 41 3a 44 0f b7 49 3e 83 e0 0f 48 0f a3 c2 73 21 69 41 28 e8 03 00 00 31 d2 41 f7 f1 31 d2 89 06 69 41 2c e8 03 00 00 <41> f7 f0 89 07 e9 d7 d8 7e e9 44 89 c8 45 89 c1 41 89 c0 eb d4 66 [ +0.000005] RSP: 0018:ffffa8df0de6b8a0 EFLAGS: 00010246 [ +0.000006] RAX: 00000000000003e8 RBX: ffff9ac65c1f6e00 RCX: ffff9ac65d055500 [ +0.000003] RDX: 0000000000000000 RSI: ffffa8df0de6b8b0 RDI: ffffa8df0de6b8b4 [ +0.000004] RBP: ffff9ac64e7a5800 R08: 0000000000000000 R09: 0000000000000a00 [ +0.000003] R10: 00000000000000ff R11: 0000000000000054 R12: ffff9ac6d0700010 [ +0.000003] R13: ffff9ac65d054f00 R14: ffff9ac65d055500 R15: ffff9ac64e7a60a0 [ +0.000004] FS: 00007f869ea00640(0000) GS:ffff9ac970080000(0000) knlGS:0000000000000000 [ +0.000004] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.000003] CR2: 000055ca701becd0 CR3: 000000010e7f2000 CR4: 0000000000350ef0 [ +0.000004] Call Trace: [ +0.000007] <TASK> [ +0.000006] ? __die_body.cold+0x19/0x27 [ +0.000009] ? die+0x2e/0x50 [ +0.000007] ? do_trap+0xca/0x110 [ +0.000007] ? do_error_trap+0x6a/0x90 [ +0.000006] ? dm_get_plane_scale+0x3f/0x60 [amdgpu] [ +0.000504] ? exc_divide_error+0x38/0x50 [ +0.000005] ? dm_get_plane_scale+0x3f/0x60 [amdgpu] [ +0.000488] ? asm_exc_divide_error+0x1a/0x20 [ +0.000011] ? dm_get_plane_scale+0x3f/0x60 [amdgpu] [ +0.000593] dm_crtc_get_cursor_mode+0x33f/0x430 [amdgpu] [ +0.000562] amdgpu_dm_atomic_check+0x2ef/0x1770 [amdgpu] [ +0.000501] drm_atomic_check_only+0x5e1/0xa30 [drm] [ +0.000047] drm_mode_atomic_ioctl+0x832/0xcb0 [drm] [ +0.000050] ? __pfx_drm_mode_atomic_ioctl+0x10/0x10 [drm] [ +0.000047] drm_ioctl_kernel+0xb3/0x100 [drm] [ +0.000062] drm_ioctl+0x27a/0x4f0 [drm] [ +0.000049] ? __pfx_drm_mode_atomic_ioctl+0x10/0x10 [drm] [ +0.000055] amdgpu_drm_ioctl+0x4e/0x90 [amdgpu] [ +0.000360] __x64_sys_ioctl+0x97/0xd0 [ +0.000010] do_syscall_64+0x82/0x190 [ +0.000008] ? __pfx_drm_mode_createblob_ioctl+0x10/0x10 [drm] [ +0.000044] ? srso_return_thunk+0x5/0x5f [ +0.000006] ? drm_ioctl_kernel+0xb3/0x100 [drm] [ +0.000040] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? __check_object_size+0x50/0x220 [ +0.000007] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? drm_ioctl+0x2a4/0x4f0 [drm] [ +0.000039] ? __pfx_drm_mode_createblob_ioctl+0x10/0x10 [drm] [ +0.000043] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? __pm_runtime_suspend+0x69/0xc0 [ +0.000006] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? amdgpu_drm_ioctl+0x71/0x90 [amdgpu] [ +0.000366] ? srso_return_thunk+0x5/0x5f [ +0.000006] ? syscall_exit_to_user_mode+0x77/0x210 [ +0.000007] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? do_syscall_64+0x8e/0x190 [ +0.000006] ? srso_return_thunk+0x5/0x5f [ +0.000006] ? do_syscall_64+0x8e/0x190 [ +0.000006] ? srso_return_thunk+0x5/0x5f [ +0.000007] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ +0.000008] RIP: 0033:0x55bb7cd962bc [ +0.000007] Code: 4c 89 6c 24 18 4c 89 64 24 20 4c 89 74 24 28 0f 57 c0 0f 11 44 24 30 89 c7 48 8d 54 24 08 b8 10 00 00 00 be bc 64 ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: drm/modes: Avoid divide by zero harder in drm_mode_vrefresh() drm_mode_vrefresh() is trying to avoid divide by zero by checking whether htotal or vtotal are zero. But we may still end up with a div-by-zero of vtotal*htotal*...Show less

In the Linux kernel, the following vulnerability has been resolved: ad7780: fix division by zero in ad7780_write_raw() In the ad7780_write_raw() , val2 can be zero, which might lead to a division by zero error in DIV_ROUND_CLOSEST(). The ad7780_write_raw() is based on iio_info's write_raw. While val is explicitly declared that can be zero (in read mode), val2 is not specified to be non-zero.Show less

In VideoFrameScheduler.cpp of VideoFrameScheduler::PLL::fit, there is a possible remote denial of service due to divide by 0. This could lead to remote denial of service with no additional execution privileges needed. User interaction is needed for exploitation.Show less

In the Linux kernel, the following vulnerability has been resolved: media: v4l2-tpg: prevent the risk of a division by zero As reported by Coverity, the logic at tpg_precalculate_line() blindly rescales the buffer even when scaled_witdh is equal to zero. If this ever happens, this will cause a division by zero. Instead, add a WARN_ON_ONCE() to trigger such cases and return without doing any precalculation.Show less

In the Linux kernel, the following vulnerability has been resolved: staging: iio: frequency: ad9832: fix division by zero in ad9832_calc_freqreg() In the ad9832_write_frequency() function, clk_get_rate() might return 0. This can lead to a division by zero when calling ad9832_calc_freqreg(). The check if (fout > (clk_get_rate(st->mclk) / 2)) does not protect against the case when fout is 0. The ad9832_write_frequency() function is called from ad9832_write(), and fout is derived from a text buffer, which can contain any value.Show less

In the Linux kernel, the following vulnerability has been resolved: iio: adc: ad7124: fix division by zero in ad7124_set_channel_odr() In the ad7124_write_raw() function, parameter val can potentially be zero. This may lead to a division by zero when DIV_ROUND_CLOSEST() is called within ad7124_set_channel_odr(). The ad7124_write_raw() function is invoked through the sequence: iio_write_channel_raw() -> iio_write_channel_attribute() -> iio_channel_write(), with no checks in place to ensure val is non-zero.Show less

In the Linux kernel, the following vulnerability has been resolved: ALSA: firewire-lib: Avoid division by zero in apply_constraint_to_size() The step variable is initialized to zero. It is changed in the loop, but if it's not changed it will remain zero. Add a variable check before the division. The observed behavior was introduced by commit 826b5de90c0b ("ALSA: firewire-lib: fix insufficient PCM rule for period/buffer size"), and it is difficult to show that any of the interval parameters will satisfy the snd_interval_test() condition with data from the amdtp_rate_table[] table. Found by Linux Verification Center (linuxtesting.org) with SVACE.Show less

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: Fix zero-division error when disabling tc cbs The commit b8c43360f6e4 ("net: stmmac: No need to calculate speed divider when offload is disabled") allows the "port_transmit_rate_kbps" to be set to a value of 0, which is then passed to the "div_s64" function when tc-cbs is disabled. This leads to a zero-division error. When tc-cbs is disabled, the idleslope, sendslope, and credit values the credit values are not required to be configured. Therefore, adding a return statement after setting the txQ mode to DCB when tc-cbs is disabled would prevent a zero-division error.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Initialize denominators' default to 1 [WHAT & HOW] Variables used as denominators and maybe not assigned to other values, should not be 0. Change their default to 1 so they are never 0. This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Initialize get_bytes_per_element's default to 1 Variables, used as denominators and maybe not assigned to other values, should not be 0. bytes_per_element_y & bytes_per_element_c are initialized by get_bytes_per_element() which should never return 0. This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity.Show less

In the Linux kernel, the following vulnerability has been resolved: ext4: check stripe size compatibility on remount as well We disable stripe size in __ext4_fill_super if it is not a multiple of the cluster ratio however this check is missed when trying to remount. This can leave us with cases where stripe < cluster_ratio after remount:set making EXT4_B2C(sbi->s_stripe) become 0 that can cause some unforeseen bugs like divide by 0. Fix that by adding the check in remount path as well.Show less